While longer daylight hours may energize us, it is warmer temperatures that really get plants and insects going.
During colder winter months, most plants and insects don’t do much. It isn’t until a certain number of days are spent within a range of warmer temperatures that growth can resume. This combination of time and temperature is called physiological time. The physiological time needed by any particular organism stays relatively the same, much like the chilling hours required of certain fruit and nut trees to produce a good crop. Physiological time is expressed in degree-days (°D), also know as growing degree-days (GDD).
How are degree-days used?
The number of degree-days needed for any particular species to move from one developmental stage to another (phenology) is still being researched, but you can this information to help you predict germination, vegetative growth, bloom times, and harvest time. Degree-days are also very important when using pheromone traps and other pest controls for things like San Jose scale. Beekeepers are beginning to look into degree-days as a way to predict colony lifecycle.
Generally speaking, degree-days needed by warm weather crops are those with temperatures between 50°F and 95°F, while cool weather crops have a low end temperature of 40°F. These thresholds can also vary by individual species. When temperatures drop below the lowest temperature, called the baseline, development stops. Above that range, development slows or cuts off altogether. Baselines of common garden plants:
35°F - onions
38°F - carrots
39°F - strawberries
40°F - asparagus, barley, beets, broccoli, collards, lettuce, oats, peas, potatoes, rye, wheat
45°F - squash, sunflowers
50°F - beans, corn, musk melons, peppers, sorghum, tomato
55°F - cucumber, watermelon
60F - eggplant, okra, sweet potatoes
There are several different models used to calculate degree-days, but, here in the U.S., they all boil down to the same basic idea. Degree-days are calculated first by adding that day’s high and low temperatures and diving by 2 for a mean temperature for the day. A plant’s baseline temperature is then subtracted from that mean temperature, for a number of degree-days counted for that day. For example:
Low 54°F (84 + 54) / 2 = 136 / 2 = 66 mean temperature
Base 50°F 66 - 50 = 16 degree-days
Unless you really enjoy this sort of thing, you do not need to worry about calculating degree-days for yourself. Agricultural researchers have already done that work for you. You can look up your local degree-days using the UC Davis CA weather data (assuming you live in California). You can also try OSU’s Croptime calculator. Or, you can invest in your own weather station and generate a more accurate, customized model. Since each garden and neighborhood is its own microclimate, the degree-days reported are only estimates anyway, but these estimates can give you the advantage when controlling pests and caring for your plants.
Degree-days to maturity
Most seed packets offer a “days to maturity” number. This number is a statistical average spread out over the entire country. Factor in things like local climate, drought, pests, and disease, and you can see that these averages are only marginally useful. You can use weather station information to generate your own, more accurate days to maturity measurement. Here are the degree-days needed by a few common garden plants and pests to reach maturity:
What surprises me is that the number of degree days for common garden plants, pests, and diseases is not yet readily available.
I’ll keep you posted as the research is published.
Saddle up, garden buckaroos!
Today we are going to learn about spurs - fruit spurs, that is!
Fruit spurs are where fruit grows. Sometimes. Sometimes fruit grows on twig tips. And some fruit trees use a mix of the two. This is called their cropping behavior. Knowing which method your tree uses and being able to tell the difference between a leaf bud and fruit spur will help you make better pruning choices when training fruit trees. This is best done while trees are dormant because there are no leaves to block your view.
Leaf buds v. fruit buds
Fruit trees generate two different types of buds: fruit buds and growth buds. Growth buds can become leaves or twigs, while fruit buds hold flowers. On some trees, a cluster of leaves may end up surrounding a fruit bud, but those tend to come later in the season. Growth buds are slender and pointed. They are smaller than fruit buds, as well. Fruit buds tend to be round and fat. In some cases, fruit buds are covered with fuzzy scales. And, many times, they grow on fruit spurs.
What are fruit spurs?
Fruit spurs are stubby little twigs that grow only 1 to 6 inches long. Sometimes they grow singly along a branch, as with peaches, and sometimes they grow in clusters, as on apple trees. Depending on the type of tree, the fruit spurs may produce fruit the first year, the second year, or for several years in succession. Some fruit spurs are productive for 10 years or more!
How to use this chart
The chart above tells you the cropping behavior of many common fruit and nut trees. Using it, you can see that fig trees produce fruit laterally, on long, first year wood. This means that regular annual pruning of various branch lengths will increase fruit production. Apple trees must be treated very differently. Apple fruit buds rarely occur on long shoots, laterally (along its sides) or at the tips. Nearly all apple fruit buds are found at the end of fruit spurs. This means that you would want to avoid pruning those spurs until they have stopped producing fruit altogether. [There are apple varieties that produce fruit at stem tips, called tip-bearers, and others that use a mix of the two, called partial tip-bearers, which is why it’s a good idea to find out as much information as you can about each of your fruit trees.]
The easiest way to tell if your fruit tree produces fruit buds on spurs is to go outside and look.
Branch collars are where trees seal seal off injuries.
Picture, in your mind’s eye, a young tree growing towards the sun. Every so often, a branch starts to emerge from the side of the thickening trunk. This is what they do. Now, picture a side branch that grows in a way or a place that requires its removal. Where do you make the cut? Tree pruning is an excellent way to maintain good tree health and increase production. Doing it incorrectly, however, can kill your tree - and it's all about the branch collar.
What is the branch collar?
The branch collar, or callus roll, is the raised area that surrounds the base of every branch. This where tree growth changes from trunk to branch. You may also see a wrinkled area where a branch meets the trunk. This is called the branch bark ridge. But the branch collar is where trees produce the protective callus. Damage the branch collar and infection is sure to occur.
If you want to learn more about branch collars at the cellular level, check out Horticultural Science’s pdf Tree Branch Attachment to Trunks and Branch Pruning. In it, Alex L. Shigo describes how branch tissues develop, bringing the xylem and phloem along for the ride, to feed the new branch. Fascinating stuff!
How trees heal
When a limb is cut, the tree seals off the area with a dry covering called a callus. The callus is generated in the branch collar and slowly works its way toward the center of the cut. If the branch collar is damaged, the tree cannot seal the area off properly. Often, this is how moisture enters a tree, leading to rot and decay and, potentially, the death of a tree.
Making a better cut
Looking at each of the Bad Ideas listed above, let’s see what makes them detrimental to your tree’s health:
Instead of doing it the Wrong Way, you can put the branch collar to work for you and train your tree to grow better and stronger.
Saving seeds is a great way to save money and encourage plants that thrive in your microclimate. People have been saving seeds for over 12,000 years.
Once you have plant varieties that work for you, there is often no need to continue buying seeds. Your plants will produce them for free!
There are three steps to successful seed saving: selection, timing, and storage. But, before we learn how to save seeds, we should review some basic information about plant reproduction.
Plants produce seeds to pass on genetic information. Those seeds are produced when a female gamete is pollinated. The way pollination occurs, and the plants involved, make a big difference in what the resulting seeds will become:
Seeds produced from plants pollinated by insects, wind, and other natural mechanisms are called open-pollinated (OP). Open-pollinated seeds are more genetically diverse, which helps plants adapt to new conditions. As long as cross-pollination between a different variety does not occur, open-pollinated seeds will produce similar offspring. That being said, bees can travel for several miles, carrying pollen, so there is no guarantee of avoiding cross-pollination unless you keep your plants sequestered in a greenhouse. The nice thing is, you may end up with something more beautiful, better adapted, or tastier than what you had before! If not, you can always add it to the compost pile and try again next year. So let’s get started!
Select seeds to save
The first step is to identify which plants in your garden are open-pollinated. You can use seed packets, plant labels, and online receipts to track down this information. Personally, I have a plastic tub that contains all of my seeds and seed packets, so everything is in one place. I put seeds in envelopes and then write what it is, and where and when it was planted, on the envelope. It really helps me keep track of things! Once you have figured out which of your plants are open-pollinated, pick the ones that grow well and taste the best. Be sure to save seeds from more than one plant of a particular variety, to maintain that healthy diversity. Do not save seeds from plants that lack vigor or flavor. One trick I use is I attached colored ribbons to plants that I plan to save seeds from, using different colors to indicate early or late producing.
A note on GMOs and other seed patents: private corporations have invested in and own this genetic information. It is illegal to save, use, sell, or trade these plants and their seeds, according to the World Trade Organization’s agreement on property rights. Consider yourself warned.
Leave the very best fruits to ripen naturally on your chosen plants. With tomatoes and peppers, you can even let them get a little wrinkly before picking. Then, open the fruit and remove the seeds. With tomatoes, I just drop the gel-covered seeds onto a paper towel and spread them out a little. Next, I write the name of the plant variety on the paper towel and allow it to dry completely before storing. Pepper seeds are just scraped off the white pith and allowed to dry. Peas and beans should be allowed to dry completely on the vine. Keep in mind, however, that this tells the plant it has completed its reproductive cycle and production may begin to lag. Seeds from plants such as lettuce, carrots, and onions can be collected using paper bags tied over the top of the pollinated flower heads. Generally, I do not save those seeds. Instead, I simply let them do their thing naturally. As a result, I have onions, carrots, and lettuces growing all over my property, with zero effort on my part!
Many people suggest storing seeds in glass jars or plastic bags, after the seeds have dried completely. Unless you are absolutely sure there is no moisture, it is a good idea to include one of those silica packets you find in shoe boxes and jerky bags, just wrap it in a piece of tissue. As you already saw, I use paper envelopes stored in a secure, but not airtight plastic container, that is kept outside year round. My thinking is, this exposes the seeds to as much of the local, natural environment as possible, weeding out the weak through natural selection. However you store your seeds, be sure to label them right away. It helps if you include the plant name and variety, plus the date the seeds were harvested. Older seeds lose their vigor, so you will want to use seeds within one year for the best results. Seeds need to be kept in a cool, dry, dark place to avoid germinating at the wrong time of year or when you’re not looking.
Seed surfaces can be contaminated with bacteria, fungi, viruses, spores and nematodes. The inside of a seed can also host pathogens. This is why it is so important to only collect seeds from healthy plants. In a study conducted at UC Davis, it was found that pumpkins exhibiting surface lesions of Fusarium wilt (Fsc 1) could still be used as a safe seed source, while pumpkins that were infected all the way into the seed cavity could not.
Saving your own seeds allows you to encourage the plants that thrive in your garden. Over time, you may even create your own heirloom varieties!
The letters V, F, and N on a seed packet or plant label refer to certain types of disease resistance and pest tolerance.
All of us work to make our plants healthier. At the end of a growing season, many of us save seeds from the very best fruits and plants for next year. [If you’ve never done this before, I urge you to give it a try. I’ll write about seed saving tomorrow.] By saving and planting seeds from the best plants each year, we are choosing specimens that are better suited to our microclimate and personal tastes.
Building better plants
When we save and plant seeds from specific plants, we are cultivating certain characteristics. A more intensive method of building better plants is to purposefully pollinate one plant with the pollen of another. Taken to the far end of this spectrum, we have plants that are genetically modified in the lab. [I used to be bothered by this, until I learned that plants have been doing it to each other for a very long time. See Dodder.] These manipulations are often used to encourage certain characteristics such as color, flavor, days to maturity, disease resistance, or pest tolerance.
Disease resistance and pest tolerance
Some plants are susceptible to certain diseases, while others are not. The same is true for pest infestations. In both cases, you can generally use the disease triangle to reduce the impact pests and diseases have on your garden. The disease triangle consists of the environment, the plant, and the problem. Change one of those three and the problem can be reduced or eliminated. Installing plants that are already resistant to some of your garden’s more common problems can reduce your work load and keep your plants healthier. That’s where V, F, and N come in.
V is for verticillium wilt
The V tells you that a particular plant is resistant to verticillium wilt. Verticillium wilt is a soil-borne fungus that attacks tomatoes, peppers, berries, snapdragon, eggplant, potatoes, and over 300 other garden varieties. Plants infected with verticillium wilt exhibit chlorosis, wilting, and leaf drop as the fungi breed, blocking the flow of water and nutrients through vascular tissue. Verticillium wilt fungi can stay in the soil for several years, so infected plants should be thrown in the trash. If you have a garden patch affected by verticillium wilt, use crop rotation and plant non-host species, such as beans and other legumes, broccoli, corn, and cereal grains. Non-host species are not affected by this disease.
F is for fusarium wilt
Fusarium wilt is another soil-borne fungal disease. As these fungi (Fusarium oxysporum) reproduce, they cause bleaching, chlorosis, stunting, damping-off, and brown veins. Fusarium wilt frequently attacks peas, beans, and other legumes, tomatoes, tobacco, sweet potatoes, cucumber and other cucurbits and even banana plants. There are actually several different strains of Fusarium wilt, so you may see F, FF, or FFF, depending on which strain the plant is resistant towards. [Check with your local County Extension Office to learn which strain is in your area.]
N is for nematodes
There are good nematodes and there are bad nematodes. Bad nematodes feed on the roots of several different garden plants and fruit trees. Aboveground symptoms include afternoon wilting, chlorosis, and a general lack of vigor. To verify a nematode problem, you have to dig the plant up. Nematode feeding causes swollen areas called galls, on the roots. Roots will also look stunted and deformed.
Seeing V, F, and N is not a guarantee. It simply tells you that a particular variety of plant is resistant. Sometimes, that little extra resistance can make all the difference.
Capers are pickled flower buds.
Used to flavor to fish, poultry, sandwiches, soups, salads, and martinis, immature buds from the caper bush have been collected, dried, brined, and then pickled for over 2500 years. This plant thrives in harsh conditions, with only a little water, making it a good choice for Bay Area foodscapes.
The caper bush
Caper bushes (Capparis spinosa), also known as Flinders Rose, are broadleaf perennial evergreens that thrive in harsh conditions, with very little water. Native to Australia and Southern Eurasia, caper bushes are now naturalized throughout many Mediterranean regions. Plants can grow 2 to 3 feet high and wide, though they tend to stay low to the ground. Round or oval edible leaves are thick and leathery. Showy white or pinkish-white flowers (2-3”) feature several pale purple stamens and a sweet fragrance.
After the flowers have attracted pollinators and fertilization has occurred, caper berries emerge. Caper berries are oblong fruits that contain many seeds. These fruits are also pickled and eaten, along with the leaves. Caper bushes have strong relationships with mycorrhizae (root fungi) that help them extract nutrients from poor soils. Capers grow well on rocky areas and in soils with higher than normal salinity.
How to grow capers
You can grow your own capers from seed. Simply place fresh seeds in rich potting soil, with good drainage, and add water. Older seeds may have entered dormancy and will need stratification (cold treatment) to germinate. Caper bushes can also be grown from stem cuttings. Stem cuttings are most successful when tender new shoots are used. Instead of producing leaves at leaf nodes placed below the soil level, they produce roots. Rooting powder (auxin) is commonly applied to encourage root growth. Caper bushes produced by cuttings are generally less drought tolerant in their early years than plants produced by seed, so water accordingly. There are poisonous varieties of caper, so be sure to get your seeds or cuttings from a reputable supplier.
Caper bushes love wet springs and hot, dry summers. They grow best in USDA Hardiness Zones 8 - 10, in full sun. While they can tolerate temperatures above 100°F, they do require frost protection. Once a caper bush is well established, the root system and soil level stump may be able to withstand limited freezing temperatures.
The smallest, youngest flower buds make the best capers, so daily harvesting is recommended during the flowering season (May through August). When they are ready to pick, caper buds will be dark, olive green, and about the size of a kernel of corn. (They shrink during pickling.) Caper bushes produce curved thorns, so be careful! One of the nicest things about growing your own capers is if you happen to miss a few buds, you end up with beautiful, fragrant flowers! It's a win-win situation!
The tangy flavor of capers is partly from the salt and vinegar used in brining, and partly from the mustard oil produced by the plant.
Did you know that it is capers that give tartar sauce its unique flavor? I didn’t either.
Note: If you are a Santa Clara County (CA) resident, caper bushes are on the Qualified Plants List for the Lawn Replacement Rebate. It’s an excellent way to get paid to replace your lawn with something more productive and environmentally friendly!
In the world of plant names, science rules.
Common names are usually region specific. A plant’s scientific name, however, stays the same all over the world.
The science of names
Certain scientists, called taxonomists, love to classify things. They use a system of names that show how closely everything is related to everything else, based on shared characteristics. This all started way back in the early BC’s with Dioscorides (die-oh-score-ih-day) and Theophrastus (thee-oh-frass-tis), but Pliny the Elder’s encyclopedic Naturalis Historia (77AD) is recognized as the first attempt at classifying plants (and every other living thing known at that time). It wasn’t until 1753, when Carl Linnaeus published Species Plantarum (“The Species of Plants”) that the world had a comprehensive plant naming system. Since Latin was the language of educated Europeans at that time, it is still used today as the universal scientific language. If you see a plant name followed by an L., you will know it was classified by Linnaeus.
This sorting by shared characteristics files everything into a series of increasingly specialized categories. Here is a list, using the standard garden tomato as an example:
If you have a hard time remembering the order of these classification words, try this popular mnemonic: Dear King Phillip came over from Great Spain. Or, make up your own!
Under each of these headings, there can be subcategories and super-categories, but don’t let that scare you off. The most important information is what’s on the label. The two Latin words next to a plant’s common name tell you the genus and species of that particular plant.
Genus and species
The first word is the genus, or generic name. This word is always capitalized, and either underlined or italicized. The next word, in lowercase, tells you the species, or epithet. The species is also either underlined or italicized, but it is not capitalized. The genus and species can provide basic information of growth habits and good cultural practices. Once you have a plant’s genus and species, you can get even more information from its variety or cultivar name.
When a species has a naturally occurring mutation that reproduces consistently, it is called a variety. To indicate a variety, the abbreviation var. is found after the species name. The variety name is not italicized, underlined, or capitalized. Taking the example above one step further, with a red cherry tomato, we have S. lycopersicum var. cerasiforme.
When a mutation occurs as a result of human intervention, be it through selective breeding, cultural practices, or genetic engineering, the plant is called a cultivar. Cultivars are “cultivated varieties” and you will see cv., followed by a name in single quotations to indicate the cultivar. Cultivar names are capitalized, but they are never underlined or italicized. Again, we can use the above example to see the name of my favorite yellow cherry tomato, the Sun Sugar (S. lycopersicum cv. ‘Sun Sugar’).
Scientific plant naming - then and now
In its early stages, plant taxonomy was based on obvious shared characteristics, such as whether a plant produced seeds or spores, was vascular or non-vascular, and whether it was herbaceous or woody. This method worked well enough for a time. With the advent of genetic testing, plant naming, or botanical nomenclature, has gone through some changes. This is why you may see two different Latin names for the same plant. In fact, there are currently several different classification systems vying for dominance in the world of plant names, which is why it took me so long to write this post!
The most important information to take from this post is to take the time to read those plant labels. Reputable growers are far more likely to sell you what is described on the label. Unreliable growers, not so much. Reading the label can give you a starting point when researching plants that you would like to grow in your garden or foodscape.
In some plant descriptions, you may read that they ares “strongly accrescent” or “scarcely accrescent.” What does that mean?
Accrescent refers to a plant or plant part that continues to get larger as it gets older.
Most plants and plant parts are hardwired to stop growing once they reach a specific size. These sizes vary by individuals because of irrigation, nutrition, temperatures, sunlight, pests and disease, but the estimates are generally true. Other plants, or plant parts, never stop growing in size, or they may continue to grow beyond the rest of the plant until some developmental stage is reached.
Degrees of accrescence
The degree to which a plant is considered accrescent can vary quite a bit. In some cases, only the peduncle, or flowering stem, is accrescent, and then only until the flower reaches maturity. These plants are rated as slightly accrescent.
Most commonly, it is the calyx that is accrescent. Calyx, or sepals, are the green modified leaves that surround the base of a flower. The papery covering seen on tomatillos (Physalis philidelphica) is an example of moderate accrescence of the calyx. When the calyx stops growing, your tomatillos are ready to harvest.
Plants that are rated as “strongly accrescent” take the challenge to grow very seriously. These plants just keep getting bigger. Giant sequoias are an extreme example of accrescence.
Understanding accrescence can help you identify unknown plants. It can also help you to know when to harvest your tomatillos!
In the world of plants, climbers have access to more sunlight and better airflow than many of their low-growing neighbors. Plus, these climbers don’t have to invest time and resources into generating a substantial trunk. Most people believe that all climbing plants are vines of one sort or another, but that is not accurate. There is an entirely separate category of climbing plants known as bines.
Bines or vines?
Vines use specialized stems (suckers and tendrils) to grab tiny handholds on their support, be it a fence, cattle panel, or a tree. Bines grow skyward by winding shoots into a helix around a support. Some people claim that bines spiral in a specific direction because of residing in the northern or southern hemispheres, but the direction of growth is species specific, rather than based on location.
Common bine plants
There are several bines commonly found in gardens and landscapes. The most common garden bines include:
Which bines are growing in your garden?
Do your basil plants wither into oblivion each summer? Do frost sensitive lettuces lose their flavor after a severe cold snap? You can use agroforestry to stabilize temperatures and reduce erosion and wind damage in your garden or foodscape.
What is agroforestry?
Technically, agroforestry refers to the intentional addition of trees and shrubs into crop and animal farming for economic, environmental, and social benefits. To qualify as agroforestry, four conditions must be present:
There are five different agroforestry systems: alley cropping, forest farming, riparian forest buffers, silvopasture, and windbreaks. In each case, you can take the basic principle and modify it to benefit your home garden.
The alley cropping method of agroforestry plants fruits, vegetables, herbs, grains and more between rows of immature trees. The trees provide protection while still allowing adequate sunlight to reach the other crops. Growing dwarf fruit and nut trees in your foodscape allows you to do the same thing year after year.
Forest farming, also known as multi-story cropping, uses the shade provided by a forest canopy to grow herbs and other edible plants, as well as ornamentals, that perform better in shady environments. You can apply the same principle by planting shade-loving and sun-sensitive plants under existing trees.
Riparian forest buffers
When something is riparian, you will know that it is alongside a stream or creek. Riparian forest buffers can be natural or artificial plantings of trees, shrubs, and grasses along waterways. In nature, the roots of these buffer zone plantings stabilize the ground and filter runoff. In your yard, you can install an artificial creek that increases biodiversity. You can even add some fish and try growing watercress, if you feel like it!
Silvopasture gets its name from the word ‘sylvan’, which refers to the woods. Silvopasture is the practice of incorporating trees and shrubs into pastureland to improve life for livestock and their forage crop. These plantings can also provide fruit, nuts, and timber, as an added income. While silvopasture is normally applied to cattle, you can do the same thing by building chicken coops around trees, or adding trees and hardy shrubs to your chicken run. In each case, the animals get food, shade, and shelter from these plants.
Rows of trees can be used to create a windbreak. These barriers work the same way as fences, providing protection for plants, animals, buildings, and soil against wind, snow, dust, and even bad smells. These barriers increase biodiversity by providing habitat and food for local wildlife. These windbreaks are also known as hedgerows, shelterbelts, or living snow fences. Hedges and rows of trees on your property can provide the same benefits. You can get a bonus when these plants are also edibles.
Each of these agroforestry methods take advantage of natural processes to create sustainable, environmentally friendly conditions that help plants and soil stay healthier, with less effort on our part. These vegetative barriers also reduce erosion, improve air and water quality, increase biodiversity, and provide more opportunities for growing your own food or selling marketable crops.
Adventitious roots are different from other roots.
Roots are generally classified as primary or lateral. The primary, or main, root supports a number of side, or lateral roots. Root systems feature either a taproot or fibrous roots. Carrots are an example of a taproot. Fibrous root systems are more “all over the place”. In both cases, the roots are attached to the aboveground portion of the plant at the crown, or to other roots. This is not the case, when it comes to adventitious roots.
What are adventitious roots?
Adventitious roots emerge from a variety of non-root locations, and for different reasons. Unlike the classic, “stem goes up, roots go down” type of growth, adventitious roots appear at leaf and stem nodes, and at wound sites. What starts out as a normal bud or shoot can change its purpose and become an adventitious root. This often occurs as a result of low oxygen levels (flooding, burial) or high ethylene levels (pollution). Several different plant hormones can trigger this response, including auxins, cytokinens, gibberellins, abscisic acid, and ethylene. These roots are the ones that appear after you break a Jade plant leaf off of a parent plant. The wound dries and new cells form just underneath the callus. Some of those cells turn into adventitious root cells that allow the leaf to become an individual plant.
Where are adventitious roots found?
Adventitious roots resulting from normal growth are classified according to where they occur on the plant:
Why do plants create adventitious roots?
As with everything else plants do, it’s all about genetic survival. Under normal conditions, many plants have evolved to use adventitious roots to access more food and water, provide greater stability, or to procreate. Bulbs use adventitious roots to send new bulblets out over a greater area. When plants are faced with conditions such as flooding, stem burial, grazing, and nutrient deficiencies/excesses, adventitious roots are used to help the plant recover. These roots may form at any of the above mentioned locations, depending on the stressor and the plant species.
How do we use adventitious roots?
Adventitious roots are why we can propagate many plants from cuttings. Grape, apple, succulent, and stone fruit species are commonly cloned in this way. Tomato plants are often planted with the first set of stems buried below the soil level. This stimulates adventitious root growth, providing the plant with more water and nutrients, ergo better tomatoes. Tomato and pepper plants are often propagated with cuttings, to extend the growing season. Plants grown from cuttings tend to mature more quickly than those started from seeds. Many herbs, such as basil, rosemary, thyme, and sage can be grown from cuttings, thanks to their ability to generate adventitious roots.
Acaulescent is the word used to describe plants with no visible stem. [It is pronounced a-kaw-LE-sent.]
Most plants have one or more central stems that support the aboveground portion of the plant. These plants are called caulescent. Acaulescent plants do not appear to have stems. Instead, these plants tend to grow their leaves close to the ground in a clustered, rosette, or whorled pattern, common of many succulents. Some acaulescent plants can get quite tall, but these are generally still leaves growing out of the ground. Now, don’t be fooled. Acaulescent plants still have a stem, it’s just extremely short and the internodes (the spaces between nodes) are densely contracted.
How acaulescent plants grow
You may be thinking that many succulents have long stems that support flowers, and you would be right. Those inflorescence axis stems are called peduncles. Unlike a trunk or central stem, these growths are purely reproductive and not structural. Many acaulescent plants have modified underground stems, such as rhizomes, bulbs, or tubers. Instead of sending up a central stem, acaulescent plants put leaves out from the crown. Some of these leaves are thick and mucilaginous, as with succulents, while others are the familiar broad leaves of many tropical plants. The stems you do see attaching the leaves to the crown are actually part of the leaf. These leaf stems are called petioles.
Examples of acaulescent plants
Aloe, agave, and yucca are popular acaulescent plants. Most bulbs, including onion, garlic, chives, and crocus, are acaulescent. The aboveground growths you see in these plants are specialized leaves called scapes. Dandelions, carrots, pineapple, cilantro, lettuce, spinach, and California poppies are also acaulescent. In each case, leaves emerge from a ground level base. Some species of cycad, primrose, oxalis (Oxalis triangularis), and palm (Attalea cuatrecasana) are also acaulescent.
Why should you care?
Knowing that a plant is or is not acaulescent will not change the way you care for it or harvest it. What this information will help you do is to identify those mystery plants that keep turning up in your garden or foodscape.
Knowing words such as acaulescent makes you sound pretty smart, too!
We all know when a gym bag is ripe, but what about the fruits and vegetables in your garden?
According to the dictionary, ripe refers to fruit or grain that has developed to the point of being ready to harvest and eat. Okay, so that rules out all those leafy vegetables, such as chard and spinach, that we can eat whenever we feel like it. That definition also pushes herbs to the side. With grain being the fruit of a cereal grain, it looks like ripeness only applies to fruit. But what (or who) decides when a fruit is ripe or not?
An unripe fruit
If you have ever tried eating an unripe fruit, you know that the experience can be less than satisfying. Starchy, bitter, and tough, unripe fruits are very unlike the ripe versions of themselves. Some fruits, such as lychee and Chinese lantern berry, can be downright dangerous to eat unripe. Unripe apples and plums are safe, but eat too many and you’re in for a stomach ache. And, if you happen to bite into an unripe persimmons, be prepared to feel like the inside of your mouth caved in on itself. So how do these hard, green, astringent fruits turn into the soft, juicy sweetness we love?
It’s all about ethylene
The lowly ethylene molecule is responsible for many changes within a plant. Ethylene is used by plants in respiration and to inhibit the movement of auxins, a plant growth hormone. By manipulating auxin levels, plants use ethylene to stimulate seed germination and adventitious root growth. It is also used to bend the plant toward the sun (epinasty). This ripening, or aging, hormone also triggers abscission (leaf and ripe fruit drop), chlorophyll destruction, flower drop, and all the signs of senescence (deterioration related to aging).
The physics of ripening
Fruit is food for seeds and seed spreaders. When a fruit falls to the ground, it provides easy access to important nutrients to the seed or seeds contained in that fruit. It also attracts animals that may help the plant disperse its seeds over a wider range. There’s no sense in attracting fruit eaters if the seed isn’t ready. Just as the seed(s) approach maturity, a series of chemical changes take place within a fruit. That’s when ripening kicks in. We all know that, as a fruit ripens, it becomes sweeter and softer. Generally, fruit becomes less green and more colorful as it ripens, too. This is because enzymes are breaking down the chlorophyll. [One study found that birds of different continents prefer different colors of ripe fruit.] This sweetening and softening is the result of certain enzymes breaking starch down into various sugars, such as fructose, glucose, and sucrose. [Any time you see a word ending in -ose, it’s a sugar.]
Natural vs. artificial ripening
Fruit can be ripened artificially, or it can be allowed to ripen naturally. Naturally ripened fruit takes longer and is less well suited to storage and shipping. It also has higher sugar levels, more complex flavor, and better texture. Fruits are artificially ripened using ethylene and acetylene gases in pressurized, temperature-controlled containers.. These methods are used by most large-scale fruit sellers. These fruits are picked green to allow for shipping and storage. But, before anyone starts bashing Big Agriculture for the problems they create, we have to give them credit for the Big Problem they have helped prevent: starvation on a very large scale. Figuring out how, and investing the necessary capital, to make such large quantities of food available year round is no small task, and I am grateful that they do. It is estimated that as much as 80% of all fruits are ripened artificially. [Check out thiat link and give it a read]. Unfortunately, as you saw in the linked article, too many ripening facilities use chemicals, such as calcium carbide, that are known to be unsafe. [I just learned that a glove is being developed that can tell if a fruit is ripe or not!]
Even if a fruit is artificially ripened safely, it will still lack the flavor found in a naturally ripened piece of fruit. This is because artificially ripened fruits may look ripe, but they may not actually be ripe. As a fruit ripens, sugar levels increase. You can see a detailed study on sugar levels and ripeness here. Reaching that state of perfect ripeness takes time. So, I grow my own and urge you to do the same. Your sun warmed, fully ripened tomatoes, cucumbers, apples, apricots, and other home grown fruits have the time they need to reach their peak of flavor, sweetness, and texture.
Some home canners claim that underripe and overripe fruits will float and just right fruits will sink, but this isn’t always true. Floating is related to density, so that rule is very species specific. Generally, smell is the best indicator of ripeness we have, unless it’s a cranberry.
Ripe cranberries bounce.
People have gone ape over bananas for a very long time - but can you grow your own?
The answer is, yes, you can!
Native to Indomalaya and Australia, bananas are believed to have been first domesticated in Papua New Guinea around 6,000 years ago.
Bananas are the world’s largest herbaceous flowering plant. Standard banana plants can reach 45 feet in height, but most end up only 16 feet tall. Dwarf varieties can range from 4 to 12 feet in height. According to Guinness World Records, the largest bunch of bananas held 473 bananas and weighed in at 287 pounds!
The banana plant
Most people refer to the banana plant as a tree, but it isn’t. Bananas plants are perennial herbs that grow from rhizomes. (If you recall, rhizome are underground stems that grow horizontally and herbs, in this case, are non-woody plants.) The fruit, technically, is a berry. The trunk of a banana plant is a false stem, called a pseudostem, made from tightly wrapped leaf sheaths that grow out of a mat or stool, called a genet, that forms a crown.
Each year, from the genet, new shoots will emerge to replace the parent plant, after its fruiting cycle is complete. The first lateral shoots to come through the soil surface are called peepers. As they grow, they are called suckers. There are two types of suckers: water suckers and sword suckers. Water suckers have broad leaves and a small rhizome base. These do not develop into plants strong enough to support a crop. Sword suckers are just the opposite, with a large rhizome and narrow leaves. Newly emerged leaves that are still rolled up are called cigar leaves and they are very fragile. Once foliage leaves are present, they are called maidens. The sucker selected to replace the parent plant each year after fruiting is called the follower or ratoon.
From the central growth of leaves, a floral stem or aerial true stem, also called the banana heart, emerges with a cluster of female (pistillate) flower. Each of these female flowers develop a seedless berry by parthenocarpy (fruit development without fertilization). These flowers are arranged into two rows that, ultimately, become a bunch, or hand, of bananas. Before that happens, however, those female flowers become longer and skinnier. Then, the far end of each female flower becomes a male flower! These males may or may not produce fertile pollen. Sometimes, in-between the female and male flowers, a third, hermaphroditic, flower emerges. These neutral flowers do not produce pollen or fruit.
Bananas as food
We are all familiar with the edible fruit of a banana, but, the banana flower is also edible in the same way that an artichoke flower is edible, except that they will stain your hands the way a beet can. Traditionally, the hands are rubbed with oil before handling these flowers. You need to remove the tough outer petals to reveal the tender heart. It is actually the bracts that are eaten. Bracts are modified leaves that surround the base of an individual flower. The outer petals look like giant pink Belgian endive leaves and make attractive food containers. Also, the leaves and petals are often used much like corn husks and grape leaves are used to wrap other foods for cooking.
Modern dessert bananas evolved from two wild seed-producing predecessors: Musa acuminata and Musa balbisiana. There are three major types of domestic banana:
From there, a genetic system of cultivar identification has been developed, but we won’t be heading down that rabbit hole. It is enough to know that there are dozens of cultivars, including:
[Note: there is no botanical distinction between plantains and bananas.]
Because banana plants grow so quickly and look so nice, some people grow them simply for looks. This means you need to be on the lookout for ornamental varieties when shopping for a banana plant. Ornamental varieties include Ensete ventricosum, Musa ornata, and Musa sikkimensis ‘Red Tiger’. These will never produce fruit.
How to grow a banana plant
Being a tropical plant, bananas prefer heat, humidity, and sun. They generally do not handle wind or compacted soil very well, so be sure to select a site that is sheltered and has good drainage. You can improve a suitable site by digging in some aged compost ahead of time. [I just ordered my own banana plant and will keep you posted on its development.]
Growing bananas in a container
Because banana plants are actually rhizomes, it is easier than you might expect to grow one in a container. You will probably want to grow a dwarf variety. The container needs to be at least 24 inches deep. If you live in USDA Hardiness Zones 9 to 11, you will want to keep your containerized banana in the shade during summer afternoons, and bring it indoors over the winter, while the plant is young.
Ripe bananas look different to certain animals. Some animals, such as zebra finch and reindeer, are able to see ultraviolet light. When they look at a ripe banana, it glows! If you have one of those handy dandy dollar bill checkers, you can see for yourself:
Commercially grown bananas are often picked green and shipped in giant plastic bags that have been sprayed with pesticides. Bananas produce a lot of ethylene gas, a ripening agent, when temperatures are warm enough, so they are kept cool to prevent ripening until they are closer to where they will be sold. The yellow color that we are all so familiar with is not exactly natural for the Cavendish banana, which is the primary cultivar found in stores. This particular banana is still green when ripe. Since shoppers prefer the yellow color, these bananas are placed in pressurized ripening rooms, where they are gassed with ethylene and held at specific temperatures to ensure uniform ripening. These high tech procedures and the economies have scale have made life difficult for small scale banana growers. Today, all banana growers are facing a very big threat.
Pests and diseases of bananas
The popular Cavendish banana is facing extinction. Because most bananas are grown using monoculture and a single genome, it is very susceptible to a fusarium fungal disease called Panama disease. Panama disease fungi enter the plant from the soil and start reproducing. This fungal population explosion, in turn, clogs vascular tissue, causing the plant to wilt. This exposes unaffected parts of the plant to so much sunlight that the plant dies. This happened to ‘Gros Michel’ or ‘Big Mike’, the Cavendish predecessor. As early as the 1920s, banana shortages started to occur as a result of this fungal disease. The song, “Yes, We Have No Bananas” actually came out of those shortages! By1960, all ‘Big Mike’ banana plantations were threatened by this disease, so a decision was made to switch over to Cavendish. That worked well enough for the past 50+ years, but the Panama disease fungi has now caught up with Cavendish. Since all Cavendish plants are genetically identical, this could mean the end of the familiar banana. The same thing happened to the potato in 1845 Ireland. Growing large quantities of identical plants is a recipe for vulnerability. If that weren’t enough, there are other fungal diseases that can also infect banana plants, such as black sigatoka. Banana bunchy top is a viral disease that can attacks bananas, along with a bacterial wilt disease.
So, before the banana, as you currently know it, disappears from grocery store shelves, you may want to start growing your own!
Cation exchange capacity (CEC) is a measure of soil fertility.
The chemistry and science behind how and why a soil’s cation exchange capacity works the way is does is fascinating (and a little too complex for this venue). To put it simply, cation exchange capacity (CEC) is a measurement of how many positively charged minerals can be held by the surface of a soil particle. To learn how this affects the plants in your garden, we will need to touch up on some basic chemistry. Don’t panic - you can do this!
Everything is made up of atoms and molecules that are either positively charged (cations), negatively charged (anions), or neutral. Organic materials and clay tend to be negatively charged. This means these anions attract and hold cations, such as potassium, calcium, and iron, which are important plant nutrients. Many anions, such as phosphorus, sulfur, and boron are held in the water that is found in the spaces between soil particles. Soils with high CEC ratings generally hold onto more water, as well as nutrients. Below, you can see the electrical charge for each plant nutrient.
Plant food exists as atoms and molecules of minerals. Minerals make up 45 to 49% of a soil sample. These mineral particles come in a range of sizes, with sand being the largest and clay being the smallest. Here in the Bay Area, we have clay. Chemically, sand is relatively unreactive and neutral. The spaces between particles (macropores and micropores) tend to be large. These spaces, and the lack of an electrical charge, make it more likely that plant nutrients will be leached out, or washed away. This is why sand has a low CEC rating. Clay, on the other hand, is made up of many negatively charged secondary minerals that love to attract and hold cations. Also, the smaller particle size of clay means that it has 100,000 times more surface area than sand, in the same size sample, so there are plenty of places for attachments to occur.
Soil test results
When I had my soil tested, it came back with a CEC rating of 20.6, but what does that mean? A CEC rating of 20.6 is considered relatively high. One way to look at a CEC rating is to think of it as a power strip - just how many cords can be plugged in? CEC is measured using mEq/100g. We won’t get into it, but it basically means how many parts of something there are in a certain volume of soil. Different soil types have very different CEC ratings:
My soil’s CEC rating of 20.6 means it can hold onto a significant amount of plant nutrients. Another, related figure found on a soil test is called base saturation. Base saturation is the percentage of available connections being used. You will normally see separate figures of base saturation for calcium, magnesium, and potassium. [You can think of them as different sized electrical plugs.] Below, you can see my base saturation results with “values found” (left) and “optimal ranges” (right).
CEC and pH
Soil pH also plays a role in a soil’s ability to hold onto plant nutrients. This is because pH is a function of rogue hydrogen cations (H+) floating around in the soil. Soils with a higher, more alkaline pH, tend to have a higher CEC rating. Of course, too much of a good thing turns out to be a bad thing. If the soil becomes too alkaline, nothing can grow in it! This is true in other ways, as well. Too much ammonium (NH4+) in the soil can interfere with the uptake of potassium (K+), calcium (Ca2+), and magnesium (Mg2+). This is why soil tests are so important. Armed with the information they provide, you can look at fertilizer labels with a more informed idea of what your soil actually needs. Acidifying our local clay is one way to make more nutrients available to your plants. The opposite is true in areas with acidic soil. There is a happy medium, but soils with a higher CEC rating are more difficult to alter, when it comes to pH.
Bottom line, cation exchange capacity is a measure of your soil’s negative charge which, in turn, tells you just how many nutrients it can hold at any one time.
At exactly 8:28 AM, on December 21, 2017, the northern hemisphere of planet Earth was tilted as far away from our sun as it gets. [The Earth is actually as close to the sun as it gets between the 3rd and 5th of January, but we are tipped away, so we don’t notice.] So, how is your garden affected by winter solstice?
What is winter solstice?
Before we learn how shortening and lengthening days affect your garden and landscape plants, let’s take a moment to discuss what, exactly, is meant by winter solstice. The word solstice comes to us from the Latin words for sun (sol) and “to stand still” (sistere). Obviously, the sun and earth never really stop moving. It’s an illusion that refers to the two extremes of the Earth’s travels around the sun.
We all know that the Earth has an equator around the middle and poles at either end, except those ends are not exactly up and down. The Earth is tilted 23.5° (23.44°, if you want to be really accurate). This means, for half of each trip around the sun, the northern hemisphere is closer to the sun, while the southern hemisphere is closer the other half of the year. You can see it easily if you hold one hand up at an angle and the other up as a fist. Your fist is the sun. Move the slanted, open hand around your fist, keeping the angle pointing in the same direction the whole time. Moving from one side to the other, you will see that different parts of your open hand are closer to your fist. When either hemisphere is at the farthest point from the sun, we call it the winter solstice. Six months later, when we are as close as we will get, we call it summer solstice. So what does this have to do with gardening?
Why does it keep getting colder after the days start getting longer?
Simple logic tells us that longer days should mean warmer temperatures. Experience has taught us otherwise. But, why? Even though the days are getting longer, we will not see our coldest temperatures until January and February. It ends up that our planet’s temperatures are largely controlled by its oceans. It takes a lot of time and sunlight to heat up an ocean.
Dormancy and frost damage
Most perennial plants go into some sort of dormancy as the number of daylight hours shorten and temperatures drop. Life process are slowed, new leaves and buds stay protected within buds, and many chemical changes occur that protect the plant from winter’s cold. You can protect your garden plants from frost damage during dormancy by adding a protective layer of aged compost, mulch, straw, or even a fabric covering around and over (but not touching) your plants. Keeping plants well irrigated, but not soggy will also protect against frost damage. Maintaining a more constant temperature can help your plants avoid falling prey to one warm day that might trigger budbreak, when the following days of cold and frost would simply kill those tender new buds and shoots.
Winter solstice in history
Rather than risking stress to your plants by working in and around them in the cold, use this day, as people have throughout history, as a truer new year, to look back on lessons learned and accomplishments reached, and then forward, to new and existing goals, both in the garden and in life.
Did you know that Stonehenge was built to line up with sunset on winter solstice?
Oxalic acid - you’ve heard the warnings, telling how rhubarb leaves and other plant parts that contain oxalic acid should not be eaten. But that’s not entirely accurate. Let’s learn the truth about oxalic acid in the garden
Oxalic acid in nature
Oxalic acid is found in a surprising number of food plants that we eat every day. The trick is in the concentration. In fact, oxalates can be toxic to plants, too, but plants bind those oxalates up in crystals that they then use as tiny spears to defend themselves against herbivores. These specialized cells are called idioblasts. Oxalic acid is formed when plants burn sugars and carbohydrates as fuel. Oxalates are also used to balance calcium levels within the plant by binding to calcium molecules. This is why some people say eating high levels of oxalic acid can interfere with healthy bones and teeth, but, again, you would have to eat an awful lot, over a long period of time, to cause any real problems. By the way, our bodies produce oxalic acid out of Vitamin C., on purpose. Also, cooking plants that contain oxalic acid has not been shown to reduce oxalate levels.
Finally, armed with this information, I went out to my rhubarb plant and broke off a young leaf and ate it. The flavor was actually pretty nice, something akin to spinach, but lighter. And I lived to tell about it.
Did you know you can grow your own quinoa?
Just don’t do what I did, which was start it just as summer temperatures were reaching 100°F! Let’s learn more about this high protein, ancient grain that you can add to your foodscape.
What is quinoa?
Quinoa (Chenopodium quinoa) is a member of the Chenopod family, along with amaranth and California goosefoot. It is also closely related to beets and spinach, along with lambs quarters and wormseed. Quinoa is grown for its high protein seeds. Unlike most cereal grains, quinoa is not a grass plant, so its seeds are classified as a pseudocereal. People started farming quinoa 4,000 years ago in the Peruvian Andes, but it has been a food staple for as long as 7,000 years. One of the things that makes quinoa so special is that it contains all eight essential amino acids used by our bodies to make a complete protein molecule, plus it is gluten-free, for those suffering celiac disease.
The quinoa plant
Quinoa is a self-pollinating dicot, which means its seeds split in half and its flowers have petals that are in multiples of four or five. Unlike many other plants, quinoa flowers are green. Its leaves are broad, with tiny hairs (trichomes), and lobed. Plants can grow from 18 inches tall to over six feet. The central stem may be green, purple, or red, depending on the variety. Quinoa seeds can be black, tan, white, pink, red, or purple, depending on the cultivar. All quinoa seeds are coated with saponins, which taste bitter. This protects developing seeds from birds and other seed eaters, but the coating needs to be rinsed off before cooking and eating your quinoa. [In parts of Africa, those saponins are collected and used as a laundry detergent!] While young quinoa leaves are edible, they do contain high levels of oxalic acid, which can cause respiratory and kidney problems. But you’d have to eat an awful lot of quinoa leaves to have a problem.
How to grow quinoa
Quinoa plants are pretty rugged. They can be grown from sea level all the way up to the highest mountain tops (13,000 ft.), just give them plenty of sunlight. You will want to select a variety that is suited to your microclimate and elevation. Quinoa grows best in loose, sandy soil, which we don’t have here in the Bay Area. This means you can either grow your quinoa in a raised bed, or you can incorporate a lot of aged compost into your quinoa bed before planting. This will provide nutrients and improve drainage. Do not try growing quinoa in containers - it needs more underground space than a container can provide. Quinoa prefers a soil pH of 6.0 to 8.5, so our alkaline soil isn’t a problem. Seeds should be planted 1/4 of an inch deep and watered very gently, to avoid washing seeds away before they get a chance to germinate.
Quinoa plants prefer temperatures from 25°F to 95°F, which mean can start growing quinoa in the Bay Area in the fall. That way, your plants will be harvested long before our quinoa-killing summer heat kicks in! Quinoa plants take 90 to 120 days to mature, so plant accordingly. Freezing temperatures will sterilize quinoa pollen, so frost that occurs during flowering can be problematic. Quinoa plants have deep taproots that make them drought resistant. These plants grow very slowly during their first two or three weeks, so snipping off weeds at ground level is the best way to reduce competition without disturbing the soil. Depending on the variety planted, plants only need 10 to 39 inches of water during the growing season. In the Bay Area, in an average year, we receive 15 inches of rain, so some irrigation may be needed, but not a lot. Quinoa plants should not be watered once they start going to seed.
Quinoa pests and diseases
While quinoa seeds protect themselves with saponins, many birds will still feast on your crop. You can use netting to reduce losses. Other pests include flea beetles, caterpillars, aphids, armyworms, and the recently discovered quinoa plant bug (Melanotrichus sp.). Bacillus thuringiensis can be used to control caterpillars. According to a report from Perdue University, there are no pesticides cleared for use on quinoa. Quinoa is prone to several fungal diseases, which is why good drainage is so important. Damping off disease, downy mildews, fusarium wilt, seed rot, leaf spot, and brown stalk rot can all affect your quinoa plants.
You will know it is time to harvest your quinoa crop when the leaves turn yellow, red, or purple, and start to drop off. The difficult part about harvesting quinoa is separating the seed from the rest of the plant. Similar to harvesting stone pine nuts, this is a labor intense process. Start by snipping off as much non-seed containing plant material as possible, and allowing the seed head to dry completely. You will want to protect these seed heads from moisture, because seeds will begin to germinate within 24 hours of being exposed to water. You will know the seeds are completely dry when you cannot leave a dent in one with your fingernail. Once they are completely dry, you can gently rub the seed heads against a colander or strainer to knock the seeds loose.
Even if you don’t harvest your quinoa, adding this plant to your garden or foodscape can increase biodiversity and, hey, it’s a strikingly beautiful edible plant!
They will never jump through a hoop for you, but you can train your trees to be healthier and more productive.
Tree training helps fruit and nut trees stay healthy, produce larger crops, and avoid broken branches. Proper tree training also reduces the likelihood of pests and disease. Too much fruit and strong winds can result in broken branches. Proper training can prevent these problems. You may not want to go as far as pollarding or coppicing, but training your trees for good structure, air flow, and the retention of productive wood is always a good idea, except when it isn’t. Trees that are particularly large or unstable should never be trimmed or pruned by an amateur. It is too dangerous.
When to train trees
Most fruit and nut trees are deciduous. This means they go dormant and lose their leaves in winter. This is handy for several reasons. First, it allows you to remove leaves that may be carrying pests or diseases. Secondly, it allows you to see the true structure of your trees. This makes training them a lot easier. The only exceptions are cherry and apricot trees, which should only be pruned in summer, to avoid Eutypa dieback.
Making a proper cut
You may want to read up on pruning before you start training your trees. Put simply, you will want to make a smooth cut that is flush with, but does not cut into, the branch collar. There is no need to paint or treat these cuts. Your tree will develop a protective callus over the area, all on its own.
Tree training basics
To maintain a healthy fruit or nut tree in your backyard, you will probably want to keep it pruned to a manageable size. This is usually 6 feet tall and 6 feet wide. If it gets too large, you won’t be able to reach. Surprisingly, trees of this size can still produce a lot of fruit. As with any other pruning job, you will want to remove any dead, diseased, or damaged limbs. You will also want to eliminate one of any pair of crossed branches. These will tend to rub against each other, creating points of entry for pests and disease. As you prune, try to work from the inside out and avoid leaving stubs. You can orchestrate the direction new twigs will take by cutting just above buds that face in the direction you want the new twigs to grow. Do not use downward facing buds as these tend to be weak and break easily. Your overall goal should be to expose the tree’s interior to more sunlight, without risking extensive sunburn damage.
The big picture
Before cutting, take the time to really look at your tree’s structure and shape. Learn what is typical for that particular species, and think about what you want from your tree over the next several years. Consider issues such as wind exposure, shifting shade patterns, fruit and leaf litter, and tree maintenance. What is proper training for a tree in one location may be completely inappropriate in a different location. If you’re not sure, ask me. You can also look at this fruiting wood characteristics chart, from UC Davis, that can help you decide what to remove and what to leave for another year. Once you have really looked at your tree and prepared your tools, you will need to select the training style best suited to your tree species. The lowest branches are usually at knee height, regardless of the style chosen.
The central leader training style is best suited to semi-dwarf and standard size trees. This style features a single main, vertical trunk. Competing upright shoots are removed and an alternating spiral of lateral branches is encouraged. This is your classic Christmas tree shape.
Modified central leader
The modified central leader style allows more sunlight into the center than a central leader system. To create this shape, a tree is first trained as a central leader, until it reaches the desired height. Then, the central trunk is topped, or removed, just above the most recent lateral growth. This causes the tree to develop more of an open center. This method is particularly good for cherries and pears.
The open center style seems to be the most popular for backyard orchards. In this style, three or four low-growing scaffold (main) branches are encouraged, with the center kept open, like a bowl. Lateral (horizontal) branches make up the sides of this bowl shape and are trimmed back to approximately 30 inches. Fruiting wood will grow from these branches. This method provides good sun exposure and air flow. Also known as vase-shaped training, it is a good method for almonds, Asian pears, and European plums.
The “Y” system
The “Y” system features two scaffolding branches, heading in opposite directions, creating a “Y” shape. Look at it as a two-dimensional open center style. This method is particularly good for peaches and nectarines. It can also be used for apples, plums, cherries, and pears.
Espalier training is a trellising system used to create a two dimensional shape. This method works well alongside driveways, paths, buildings, and fences.
If you end up removing smaller, new wood, you can save these and use them as scions, to create new trees or modify existing trees. They may good gifts for fellow gardeners, as well!
Also, as you work closely with your tree, keep a look out for scale and other insect pests that may be overwintering in your tree’s bark.
Barley was one of the first grains ever grown domestically. It was cultivated in Eurasia 10,000 years ago ~ before people had even figured out how to make pottery!
Barley has been used as food, fodder, and currency. Barley is cited as a reason for many prehistoric cultures to develop into cities capable of maintaining armies, because of its ability to be stored. Barley beer is believed to be the first alcoholic beverage, created by Neolithic people, who malted* the grains. Rations of barley were given to workers since ancient times. Barley is still used today to make beer, whiskey, porridge, bread, soups and stews. And the U.S. and the U.K. still base their shoe sizing on the size of a barely corn (seed).
The barley plant
Barley (Hordeum vulgare) is a member of the grass family (Poaceae). It is a self-pollinating annual. Barley has a relatively short growing season, but it tolerates cool weather and drought, making it a good winter crop, here in the Bay Area. Barley seeds grow on a brittle spike, made up of spikelets. When the seeds mature, the spikelets fall apart, allowing the seeds to spread. The long hairs that stick up are called awns. There are two main types of barley, based on the way the seeds are arranged along a central stalk (rachis) and their fertility: two-row barley and six-row barley. In six-row barley, all of the seeds are fertile, whereas only one in three of the two-row barley are fertile. Two-row barley has less protein and more starch than six-row barley, making a better choice for malting and fermenting. Higher protein six-row barley is more commonly used for animal feed. There are spring and winter varieties of barley, depending on whether or not they need a period of cold to transition into their reproductive phase. In the Bay Area, that generally means planting in either October or January. Barley’s reproductive phase is characterized by true stems, called culms, carrying flowering heads, also known as a spikes or ears, that emerge from the sheath, or boot. surrounding the uppermost leaf (called the flag leaf). Barley grows 2-1/2 to 3 feet tall.
Barley seeds have tough coverings called hulls. Most varieties have hulls that are difficult to remove without losing or damaging some of the grain. These are also known as ‘covered’ barley. The barley you see in the store is usually hulled or pearled barley. Hulled barley is a whole grain, but pearled barley is not. Pearling removes several outer layers of the grain along with the hull. There are also hulless, or ‘naked’ barley varieties, but they aren’t really hulless. Instead, the hull is simply easier to separate from the grain. Barley hulls are often used to make pillows.
Why grow barley?
You may want to grow a small patch of barley, simply as a testament to our agricultural history, to know that you can. You may want to try making your own beer or whiskey. You may want to grow more of your own ingredients for a hearty winter soup. Barley can also be grown as a cover crop or green manure, to reduce erosion, improve soil structure, and suppress weeds. Barley is an excellent crop to install as your winter fava beans start ending their growing season. If you add a legume, such as peas or beans, and leave the plants in place, you can significantly improve nutrient cycling. Barley grown in winter has a deep, fibrous root system that can go down over 6 feet! Also, because barley grows so quickly, it absorbs surface water that would otherwise be used by weeds. Barley plants also shade out weeds and the plants emit allelopathic chemicals that suppress weed growth. Barley can also be used as a nurse crop. Nurse crops provide protection for slowing growing crops, such as beets.
How to grow barley
Barley seeds are planted using a method called drilling. Drilling is exactly what it sounds like: you drill a hole in the ground and drop a seed in. Commercial growers have heavy equipment that drills and plants seeds automatically. You probably don’t have one of those machines in your garage, so you will have to do it by hand. Barley seeds are planted deeply. By deeply, I mean 2 inches deep. When I first started growing things in my California concrete soil, I actually used a battery powered drill to plant seeds. After five years of composting, mulching, and top dressing, the drill is no longer needed. Now, I use a hand weeding tool to poke a hole in the ground.
Barley does not like waterlogged soils, so allow the soil to dry out between waterings. Of course, if it’s a rainy winter, there isn’t anything you can do about it other than continuing to add organic material to the soil, to improve drainage. You can see a spreadsheet of various barley cultivars suitable for growing in California here.
Barley pests and diseases
As a cereal grain, barley is prone to fungal diseases, such as leaf scald, net blotch, stripe rust, leaf spot, and stem rust. Common pests include mites, armyworms, grasshoppers, crane flies, stinkbugs, wireworms, and aphids. Also, aphids may carry a viral disease called barley yellow dwarf. Some people claim that barley acts as a natural pesticide, but research has not shown this to be true.
So, how about making a little room for a patch of barley? As a food crop, I expect that it will be much like endive, nasturtiums, lentils, and tomatoes - it will continue to turn up long after I have stopped planting it.
* What is malting?
Malting is a method used to make grains more appropriate for beer, whiskey vinegar, shakes, and many other food products. Malting consists of soaking cereal grains in water, to stimulate germination, but then drying the seeds with hot air before germination actually occurs. This triggers certain enzymes into action that convert starches into sugars, and break down certain proteins that are later used by yeast as food. Malted grains ferment quickly and become slightly alcoholic on their own.
I hope this information inspires you to grow more of your own food. You can ask your garden questions on my Home page.