Cooling, shorter days
Succulent harvest abounds
Prepare now for cold
Harvesting the fruits of all that labor and preparing for winter keep the September gardener busy. Deadheading, clearing away debris, and composting spent annuals all help to prevent future problems with pests and diseases.
Many apple varieties are ready for harvest (assuming the birds have left any uneaten). Other apple varieties will need some colder weather to sweeten. If you notice small brown, corky areas under the skin, it is called bitter pit. Bitter pit, like blossom end rot in tomatoes, is caused by a calcium deficiency early in the spring. In this case, however, the condition can be treated on future crops by spraying the leaves with calcium nitrate just after bloom and again one or two months later. Use one tablespoon per gallon of water.
Carrots prefer loose soil, but shorter varieties perform well enough in our heavy clay. The addition of compost can help aerate the soil and provide valuable nutrients. Carrots should be planted no more than 1/2” deep and plants should be thinned to 3” apart, to avoid forking and twisting. Water regularly but allow some drying to prevent cracking. Successive plantings provides an ongoing harvest. Carrots can be planted between landscape perennials for productive use of space.
Areas of the garden that will be left bare over the winter are better planted with cover crops. Cover crops help maintain important soil microorganisms that will, in turn, support your spring and summer crops next year. Fava beans are an excellent choice in the Bay Area.
If rose leaves are exhibiting neat round or oval holes in them, it is probably the beneficial leaf cutter bee and should be ignored. The sections of leaf are used to line brood cells, which are also filled with nectar and pollen.
Squash and cucumber plants are susceptible to a disease carried by aphids and cucumber beetles. Mosaic virus causes leaves to become mottled and stunts plant growth. Fruit may become white. Diseased plants should be removed and put in the trash. Do not add to the compost pile.
As nights become cooler, it is common for powdery mildew to strike. Affected leaves should be removed and thrown in the trash, and overhead watering should be avoided.
Gnawed fruit, empty snail shells, and tiny black pellets are all signs of roof rats. These pests can infiltrate your attic, crawlspace, garage, storage shed, and trees. Rat traps are an excellent way to remove resident rats. Keeping pet and livestock food sealed up and harvesting crops as soon as possible will help make your yard less desirable to the local rat population. Since rats can carry serious diseases and damage electrical wiring, it is worth the effort to get rid of rats.
If leaf stippling and tiny webs are seen, spider mites are probably the reason. Spider mites prefer dusty conditions, so spraying infested plants with the hose can help. Using broad spectrum pesticides is not recommended because they will kill the spider mites’ natural predators. Heavy spider mite infestations can be treated with insecticidal soap or horticultural oil.
Any yellow flowers produced by your tomatoes now will not have time to mature before temperatures cause fruit to turn mealy before maturing. Instead, remove those flowers to encourage plants to put all their energy into any fruit that is already on the vine.
September is the time to plant many winter crops, including artichoke, arugula, beets, bok choy, cabbage, carrots, cauliflower, chard, cilantro, collards, dill, fennel, kale, leeks, parsnips, peas, radishes, rutabagas, spinach, and turnips.
Enjoy the fruits of your labor!
Foggy mornings pale
Seared from sight by blazing sun
Nectarine juice drips
Aside from watering, August may seem like the perfect time to take a break form the heat, but there are still plenty of garden tasks to choose from!
While ants do help aerate the soil, they can also damage crops and spread disease. Fruit trees can be protected with sticky barriers. Boric acid bait traps can be an effective control method, just be sure the baits are placed where children and pets cannot reach them.
Now is the time to be on the lookout for codling moth larva. From the outside, an apple will have a small, scabby spot. If you cut (or bite) into the apple, you will see that this spot leads to a trail that heads toward the core. You can interrupt the codling moth lifecycle by collecting and removing any fallen fruit that would provide an overwintering haven.
Unlike other trees, which are pruned when they are dormant, apricot trees are best pruned in summer. Apricot trees are susceptible to a fungus called Eutypa dieback, which can infect trees if rain reaches fresh pruning cuts.
This is the time of year when Japanese beetles, dried fruit beetles, and June beetles are the easiest to see (and eliminate). Japanese beetles will skeletonize many plants. These pests tend to cling to their favorite foods and are easy to knock into cans of soapy water. [I used to pay the neighborhood children a nickel for every June bug they eliminated - very useful in Virginia!] June bugs are clumsy fliers and easy to slap down with a net. Both can be fed to chickens. Dried fruit beetles and June bugs do not bite or sting and dogs can be trained to chase and kill them before they lay eggs in the soil. These eggs will later hatch and the larvae will devour lawn, ornamental, and other plant roots.
Just as in April and June, oranges and other mature citrus trees should be fed one-half pound of nitrogen in August. Blood meal is an excellent source of nitrogen, without all the fillers. Ammonium sulfate is another good source of nitrogen.
This is the time of year when all that hard work and patience really pay off. Keep plants healthy and enjoy the fruits of your labor by harvesting frequently. This reduces the number of places where pests and diseases can hide. This also prevents many plants from going to seed and ending fruit production. When harvesting tree fruit, be sure to keep a look out for mummified fruit. Remove mummies and dispose of them in the trash, not the compost pile.
This drought tolerant shrub is a great way to attract pollinators. After it has bloomed, cut plants back, close to the ground. This will prevent plants from becoming too leggy and it stimulates more flower development.
If you have a lawn and it has not turned completely brown, allow it to grow longer than you would in cooler months. Taller grass protects the soil and helps retain moisture. And be on the lookout for masked chafers and southern chinch bugs.
Mite infestations often look like nothing more than light webbing around leaves and stems. This webbing is followed by leaf stippling, chlorosis, and leaf drop. Water-stressed plants are more susceptible, as are dusty plants. Mites are related to spiders. Adults have eight legs, but the young only have six. Spraying pesticides often backfires because mite predators, such as lacewings and pirate bugs, are killed. Often, you can use a soft-bristled brush to dislodge these pests.
By August, most rain barrels have run dry, making this the perfect time to clean out any debris in the remaining grey water, along with any mosquito larvae. West Nile Virus, Zika Virus, and many other diseases are transmitted by mosquitoes, so it is important to regularly eliminate any standing water. Mosquito dunks should be added to any standing water every 30 days.
Hot weather means trees need more water. Trees planted in a lawn that is being watered regularly will still need a deep watering 2 or 3 times during the summer, or more, depending on the weather. Stand alone mature fruit and nut trees will need a deep watering every 3 - 4 weeks, while younger trees will need to be watered every 2 weeks. Ideally, there is an irrigation ring around each tree at the drip line.
August is an excellent time to start seeds for winter crops. Spinach, beets, lettuce, arugula, broccoli, Brussels sprouts, cabbage, cilantro, bush beans, fava beans, leeks, radishes, and peas can all be started in small containers for transplanting after summer crops are done. This gives you a head start on the cooler growing season, just be sure to keep the soil moist. A thin layer of vermiculite can help retain moisture.
Greens bolt and wither
Searing heat and glare above
Seek shade and cool water
July in California can get too hot to spend much time outside. Early morning and late evening make working in the garden far more comfortable, but leave most of the heavy work to the plants as they produce leaves, stems, and fruit in response to all that sunlight. The best things you can do for your garden in July is irrigate properly and monitor plants for pests and diseases.
Monitoring for pests and diseases
You know what they say about an ounce of prevention. Well, here are a few helpful July ideas that work to prevent problems in the garden before they have a chance to get started:
It’s all too easy to forget about the trees in your landscape, but scorching summer heat and an extended drought can be devastating. Trees are a big investment of time and space, so be sure to include them in your watering plan. The only exception is our CA live oaks - they are accustomed to hot, dry summers and watering them only makes them susceptible to disease.
There is no fixed magic formula for watering plants in the garden. There are simply too many variables, such as plant variety and age, soil type, fertilization practices, sun and wind exposure, overall plant health and life stage - you get the idea. The best way to assure that your garden plants are getting the water they need is to learn as much as you can about the specific varieties and their water needs. This information will help you to provide them with the growing conditions they need. Be sure to water tomatoes, peppers, eggplant, and squash consistently, to avoid blossom end rot.
During summer, container plants may need a drink practically every day. Just be sure to avoid overwatering - a drowning plant looks an awful lot like a plant that’s dying of thirst. An inexpensive moisture meter ($10-15) can help prevent irrigation errors. Also, be sure to get those containers up off the concrete. Even the smallest air space underneath can significantly reduce temperatures for potted plants.
If you still have a lawn, be sure to raise the blade on your mower. Taller grass shades the ground, reducing water loss and stabilizing soil temperatures. By the end of July, your lawn will probably be brown, and that’s okay. Keep watering it. The root system will stay alive, and green shoots will come back in the fall after temperatures go down. [I use water from my washing machine with no negative results and my lawn stays green far longer.]
Basil and other heat lovers
It is finally warm enough for crops such as basil, melons, eggplant, and peppers to really thrive. These are some of my favorite plants. You can train melons up a trellis or ladder, and you can never have too much basil. If you have more than you can use fresh, simply whip up a batch of pesto and throw it in the freezer. Come January, you’ll be glad you did!
Mulch and side dressings
Summer is an excellent time to mulch unused garden areas. As it breaks down, the organic material will improve soil structure and add valuable plant nutrients. This is particularly helpful if you have compacted soil. Until it does break down, mulch stabilizes soil temperatures, reduces weed competition, and helps soil retain water. In the same way, side dressing the plants in your garden or foodscape with aged compost is a trouble-free way to add nutrients to growing plants without applying chemical fertilizers.
As you lounge in the shade with an iced tea, remember that July is an excellent time to consider what cool season crops can be added in fall!
Longer days of sun
Burst forth fruits and leaves
June is a busy month in the garden. Summer heat means irrigation and ants seem to be everywhere. Fruits, flowers, and mulch are the name of the game when it comes to June garden chores.
Ants & aphids
The bane of all gardeners, aphids are in full force in June. You may see ant trails in trees or curled leaves. Ants and aphids have a mutually beneficial relationship that may not kill garden plants, but they can carry diseases that will. They can also make fruit and vegetables inedible. Monitor for ants and aphids at least twice a week. If ant trails are seen, wrap tree trunks with tape and apply sticky barriers. This sticky goo will prevent ants form protecting and farming the aphids and halt the spread of many diseases. Aphid populations can then be reduced with a powerful spray from the hose. Adding plants that attract beneficial insects will also curb aphid populations.
Armored scale are parasites that suck the living sap from shrubs and trees. In June, these difficult to control pests are in a crawler stage that is easier to defeat. Monitor plants for armored scale infestations. Apply horticultural oil (not dormant oil) every month in summer to affected plants.
Bees are out in force, collecting pollen and nectar for their families (and pollinating nearly all of our garden crops). If you see a swarm, know that swarming bees are generally not aggressive or a threat, they are simply looking for a new home. You call contact your local Bee Guild or Master Gardeners for information on swarm collection. Honey bees continue to struggle and research on colony collapse disorder is ongoing. Recent findings have shown that systemic pesticides made with neonicotinoids are adding to the threat against native bees, but not honey bees. You can do your part to help our pollinators (and protect our honey supply) by avoiding the use of insecticides and pesticides when bees are present.
Blossom end rot
Are there brown depressions on the bottom of your tomatoes? This is caused by not enough calcium or irregular watering. Since most soils have adequate calcium, watering is usually the culprit. Without regular watering, the calcium in the soil cannot reach the plant. Mulching can help. Water tomatoes regularly, allowing the soil to dry out between waterings.
Blackened twigs & branches
If twigs and branches are turning dark or burnt looking, you have a problem. Generally, the damage starts at the tips and moves toward the body of the plant. This can either be dieback or fireblight. In either case, all you can do is remove the damaged tissue, cutting well below the visible infection and cleaning your clippers with disinfectant between each cut. Take a close look at the cut to make sure healthy tissue is visible. To reduce the chance of these fungal diseases attacking fruit trees in June, reduce or halt watering during the bloom and avoid adding nitrogen. Nitrogen stimulates new growth that is especially vulnerable to infection.
In California, most soils contain adequate nutrients for citrus growth, except nitrogen. One-year old trees will need 1/10 of a pound of nitrogen, while mature trees need approximately 1-1/2 pounds. These amounts should be divided into three different feedings in April, June and August. Blood meal is an excellent source of nitrogen, without all the fillers, or you can purchase a balanced product that contains zinc. Spread the fertilizer evenly over the entire root area and water in.
QUARANTINE WARNING: MOST OF SANTA CLARA COUNTY IS UNDER QUARANTINE FOR CITRUS, DUE TO THE ASIAN CITRUS PSYLLID. CHECK THIS MAP TO SEE IF YOU ARE AFFECTED.
Container planting is an excellent way to garden in small spaces and to add art and color to the landscape. However, June’s high temperatures can dry out containers very rapidly. To make matters worse, frequent irrigation can also leach out nutrients. It’s a dilemma. Gardeners can reduce these problems by using glazed clay pots, which dry out slower than unglazed pots. Dark plastic should also be avoided because it can get too hot and cook the roots. Good drainage is important, but you can help container plants hang on to water and nutrients by using potting soil, rather than planting mix. Also, be sure to get those pots off hot concrete. By creating even a little air space under the pots, you can help them stay cool.
June usually provides an abundance of fruit. If damaged fruit is seen, take a closer look. If the fruit looks chewed on, it’s probably rats or squirrels. Personally, I use Bobbex-R to deter these destructive, disease-carrying pests. My dogs enjoy helping out, too! I also use traps to kill rats. It’s a bit disgusting, but it works.
Does the fruit show stab marks? That’s usually birds. The only way to keep birds out of fruit trees is with netting or a tree cage. The netting is a royal pain to put up and take down, but it’s surprisingly easy to build a permanent tree cage. Most birds will only take a bite or two out of dozens of fruits, ruining a crop. Netting placed directly on the plant does not protect fruit near the netting. I also discourage birds by hanging old CDs in my fruit trees and mounting shiny pinwheels in various places. Breezes cause them to spin and reflect light, which seems to alarm the birds some of the time..
Spent ornamental flowers should be removed to stimulate new growth. When deadheading, don’t clip just below the flower. Instead, look down the stem for a leaf connection that shows bud growth. June deadheading is also a good time to prune for improved shape, structure and air flow.
Another common pest, earwigs are second only to slugs and snails in garden destruction. Even though they eat aphids, the damage they cause doesn’t balance out. Trap earwigs in moist, tightly rolled newspaper or cardboard tubes. Earwigs will gather in these bundles after their nightly feeding and you can toss them in the trash in the morning.
Fruit drop and fruit thinning
Don't be concerned if your fruit trees suddenly drop a majority of their blossoms or immature fruits. This normal behavior, called June drop or blossom drop, prevents trees from producing more fruit than they can support. To help your trees create the highest quality and best sized fruit, this is the time to thin fruits.
If you haven’t already, June is a good time to check irrigation systems for leaks. Drip systems should be flushed and emitters checked for clogs. This is also a good time to test to see where, exactly, sprinklers are spraying and where they are not. There’s no sense in wasting precious water in urban drool and the spray should never hit tree trunks.
Mulching is one of the best things you can do in the garden, especially in June. Mulching stabilizes soil temperatures, reduces weeds, and helps the soil retain moisture. Aged compost, placed on top of the soil, is mulch. Tree trimmings make excellent mulch and they can be acquired for free from tree trimming companies! As mulch breaks down, it adds valuable nutrients to the soil and improves soil structure. Just make sure that mulch is kept away from tree trunks and that it isn’t too thick. Generally speaking, a layer of 3 inches is just right. Too much mulch can interfere with gas exchanges.
If you haven't started already, June is an excellent time to plant those heat loving peppers, squashes, eggplants, and melons. Also, you can create an ongoing harvest by succession planting radishes, beans, and other determinant crops.
As roses give us their lovely June blooms, they may also put out suckers. Most modern roses are actually grafted onto hardy root stock that will not produce those lovely flowers. If new growth is emerging from underground, rip them out. Desirable canes, on the other hand, will grow out of aboveground buds and should be allowed to grow (assuming they won’t result in crossed canes or poor air flow. Black spot, rust, and powdery mildew are common fungal diseases of roses. Proper pruning can reduce the chances of these diseases occurring. Diseased leaves should be removed and discarded.
Be sure to put on your sunscreen, wear a hat, and keep those tools clean and sharp as you enjoy the garden in June!
As busy as bees
We pierce the warming topsoil
With dreams of freshness
May is one of the busiest months in the garden. Temperatures have warmed enough for us to begin planting in earnest. Weeds, pests, and beneficial insects are out in force. And it's gorgeous outside!
Bees are very active in May. There is simply so much pollen and nectar to collect! Sometimes, a honey bee colony may swarm. If you see a swarm, don’t panic. As in any other time when working around bees, remain calm, move gently, and give them their space. Contact your local Master Gardeners to have swarms removed.
Bulbs & other flowers
If flowering bulbs were looking crowded during the recent bloom time, delay digging them up to separate until after all the foliage is completely dry. Bulbs pull important nutrients from these leaves to help start up again next spring. Bulbs that are dug up and separated can be replanted in a new location, gifted to friends, or stored in a cool, dry, dark location until fall. If you want fall blooms, plant now.
They are countless varieties of plants that perform well in containers. Do them all a favor in May and get them off that soon-to-be hot concrete patio. Creating even the smallest space under container plants can reduce the roasting effect, which means they will need less water. Speaking of water, warmer temperatures mean container plants will start drying out more quickly. Water as needed.
Many flowers are in full bloom in May. To encourage plants to continue creating blooms, remove spent flowers as soon as they are seen. This also reduces habitat for many pests and diseases. Pinch back borage, petunias, and fuchsias to prevent plants from becoming top heavy.
May is the time fireblight shows itself in the Bay Area. Fireblight is a bacterial disease that makes plants look as though they had been damaged by fire. It attacks apples, pear and quince, most often, but can also infect ornamentals, such as toyon and pyracantha. Very often, the growing tip folds over into a shepherd’s crook shape. Fireblight can kill a mature tree, so complete removal of any diseased tissue is critical. Dip clippers into a 1 part bleach, 9 parts water solution between each cut to prevent reinfection. The final cut should be 8-12 inches below the diseased area.
May should be the time when fruit trees are covered with immature fruits. Thin those fruits now or regret it later. Too much fruit in one place means none of them taste as good as they might have. It also creates habitat for pests and disease. Apples should be thinned to no more than 3 fruits to a cluster, or one fruit for every 6 inches of branch. Apricots and other stone fruits need 4-6” between fruits for optimal growth, flavor, and sweetness. Also, be sure to check apples for codling moth damage.
If you still have a lawn, be sure to water it as early in the morning as possible. That way, the water isn’t lost to evaporation and the grass has time to dry out during the day, reducing the chance of fungal diseases. For the most part, I use water from my washing machine to water my lawn and it has been working very well. Check the lawn for weeds such as spurge, burclover, and whatever happens to invade your neighborhood. When mowing, set the blade height as high as you are comfortable with in summer. Taller grass shades the soil. This reduces evaporation and it makes the soil more comfortable for valuable earthworms and microbes.
Mulch and compost
Compost and mulch are two of the best things to add to any landscape. They add valuable nutrients to the soil, improve soil structure, and stabilize soil temperature. In our heavy clay soil, mulch prevents the baked concrete look we have come to expect in summer. [An important note about soil additives - while it may sound right to add sand to clay soil, to reduce compaction, it ends up creating concrete. Don’t do it!]
Slugs & snails
Slugs and snails can devastate young May seedlings. Applying non-toxic slug and snail bait lightly around new planting areas can save the crop. While there are more effective baits, those made with iron phosphate are not toxic to pets and wildlife and I have found they work well enough.
This is the most welcome news of the season in the Bay Area. Nearly all summer growing plants (tomatoes, cucumbers, melons, squash, beans, corn, and peppers) can be put in the ground in May. If you are using transplants, be sure harden them off gradually or they may lose much of their vigor and productivity. Hardening-off simply means placing them outdoors in a protected location for a few hours. Slowly increase the time over a couple of weeks. Be sure to stake tomato plants now, while they are small. This can be done in tandem with quarantining new plants. And add straw under melon, squash, and strawberry plants to reduce fungal infection.
If verticillium wilt occurred last year, it is important to plant members of the nightshade family (tomatoes, potatoes, peppers and eggplant) someplace else. Verticillium wilt is a fungal disease that shows as yellowing older leaves, at first. Then, as the disease spreads, wilting occurs. Young plants nearly always die. Since the fungal spores can remain in the soil for 10-15 years, crop rotation is the best prevention.
California’s drought is continuing, despite the fair bit of rain we have received so far. The truth is, the Golden State has always been drought-prone and we would be wise to learn to live accordingly. When water restrictions were first implemented, I vowed to take meaningful steps to reduce our water consumption. As a result, we now use only 25% of the water we used to use! Surprisingly, my garden has not suffered and neither have we. These steps can help you conserve water while still caring for the garden:
Just as young garden plants are really kicking it into high gear in May, so are the weeds. Take my word for it, pulling them while they are small, and before the soil is baked, is much easier than later. Weeds take precious water and nutrients from garden plants. In most cases, the sooner they are gone, the better.
So, put on the hat and sunscreen and get out there in that May garden!
April chirps and sings
Splitting shells and seeds and blooms
April is a busy month in California gardens. With scorching summers on a not-too-distant horizon, flowers, weeds, and every other living thing are striding toward sunlight. Cool nights may hold this rampant growth in check for another week or two, but most gardeners have plenty of April garden tasks to keep them occupied.
Tree Trunk Painting
If you didn’t whitewash your tree trunks (and exposed branches) in March, there is still time to provide this valuable sun protection. Trunks and branches that get too much sun exposure can be damaged, causing the bark to split and peel. This provides pests and diseases with easy access to your trees’ inner workings. A simple mixture of half water and half white interior latex paint is all you need to protect your trees from sunburn this summer.
This is also a good time to replace last year's sticky barriers. The protection from crawling insects cannot be overstated. Sticky barriers block those crawlers (and slugs and snails) from getting up into your fruit and nut trees. This is especially helpful when it comes to ants, which will protect and farm aphids. Over time, the goo dries, making it ineffective. Also, the tape tends to pull away from the trunk, creating an easy trail for pests. Gently remove both the tape, inspect the trunk, and reapply the sticky barrier.
Codling moth larvae can devastate apple, plum, pear, and walnut crops. The larvae pierce the fruit and burrow into its core, where it then feeds on the fruit, making it inedible. On apples, look for tiny dimples with a small hole in the center. These holes are usually filled with frass (bug poop). Trees should be monitored every week for signs of infestation. Infested fruit should be removed and discarded, to break the codling moth life cycle. Pheromone traps can be hung in isolated trees, but you need to understand that these traps attract codling moths to the tree. The traps are really a population monitoring device, not a control measure. Fruit can be bagged for protection, but this is a very labor intensive method. Kaolin clay application is an excellent organic control method. Heavy infestations may require the use of pesticides on the moths, before fruit is affected.
As flowers begin blooming, you can increase production by removing spent blooms. Take a look at buds further down the stem and clip just above a bud that points in the direction you want the new growth to go. Deadheading can help the plant structurally and allow for good airflow, as well as stimulate new flower development.
As difficult as it may be for gardeners to thin out fruit and young plants, it really is necessary for the optimal growth of remaining plants. April is the time to thin fruit on fruit trees, such as apricots, peaches, apples, pears, nectarines, and plums. Crowded fruit doesn’t get as big as it could and it encourages fungal diseases. Close-quartered fruit also provides great hiding places for pests. The best fruit grows from strong flower buds in full sunlight. The basic rule of thumb for thinning fruit is to leave one fruit per spur, with fruit 4-6” apart. Apricots, nectarines and peaches are normally thinned when the fruit is 1/2-3/4” in diameter. Nut trees do not need to be thinned. Seedling plants should also be thinned according to seed packet or other reputable information. This allows each plant to reach its full potential and it reduces problems with pests and diseases.
Spring rains bring moisture that can cause many fungal diseases. Anthracnose, brown spot, powdery mildew, sooty mold, and verticillium wilt should all be watched for and treated. Many of these conditions can be avoided with pruning that allows good air flow and irrigation that does not come from overhead. Overhead watering splashes millions of fungal spores onto uninfected plants, spreading the disease (plus, it wastes water through evaporation).
Irrigation & greywater
As temperatures rise, irrigation becomes more important. Container plants will begin to dry out and need to be checked every day. If the irrigation system wasn’t inspected in March, be sure to do it now. Greywater, from sinks, washing machines, and rain barrels can be used to irrigate ornamentals and lawns. I use water collected from the shower, as it heats up, to water edibles.
To add nutrients, reduce weeds, and to help retain moisture, nothing beats mulch. Wood chips and aged compost both make excellent mulch. You can request free wood chips from local tree trimmers. To stop weeds from growing, the mulch should be at least 4” think. Be sure to keep mulch at least 8” away from tree and shrub trunks, to avoid fungal diseases, such as crown rot.
If you have Navel orange trees, the crop will be ripening in April. Oranges left on the tree too long will dry out and become inedible. Instead, harvest the entire crop by the end of the month and you can make my new favorites, Cardamom Orange Marmalade, Orange Cumin Chutney and Spiced Oranges. Once canned, these delicious condiments make lovely gifts. You’ll want to be sure to save plenty for yourself - it’s that good! Valencia oranges will ripen during the summer and they make excellent juice. April is a good time to add nitrogen for orange trees. One-year old trees will need 1/10 of a pound of nitrogen, while mature trees need approximately 1-1/2 pounds. These amounts should be divided into three different feedings in April, June and August. Blood meal is an excellent source of nitrogen, without all the fillers.
QUARANTINE WARNING: MOST OF SANTA CLARA COUNTY IS UNDER QUARANTINE FOR CITRUS, DUE TO THE ASIAN CITRUS PSYLLID. CHECK THIS MAP TO SEE IF YOU ARE AFFECTED. ALSO, BE ON THE LOOKOUT FOR ORIENTAL FRUIT FLIES. IF EITHER PEST IS SEEN, PLEASE CALL THE PEST HOTLINE AT 1-800-491-1899.
Fennel, arugula, rhubarb, and asparagus provide many years of food production and April is a good time to plant. Fennel and rhubarb will take up a good amount of space, so be sure to keep mature sizes in mind.
Temperatures have finally reached the point when gardeners can plant most herbs, leafy greens, and other salad ingredients. Lettuce, spinach, bok choy, basil, parsley, cilantro and radishes can be planted every couple of weeks (succession planting) for a continuous harvest until temperatures get too hot.
Most vegetable crops can be planted in April, here in the Bay Area. Bush and pole beans, corn, cucumber, summer and winter squash, and tomato seeds put in the soil now will begin their journey toward fruitfulness. Be sure to read packet directions for planting depth, spacing, and sun requirements for the best results.
One of the most important April garden tasks is to get rid of those weeds. Since they can go to seed faster than everything else in the garden, pulling them out now will save you countless hours of work later on, in the summer.
Nascent roots and stems
Displace freshly warming earth
Chill nights slow their birth
Citrus pruning should not be started until after March 15th, but now is the time to seriously inspect for mummies. Mummies are those shriveled up, fuzzy gray oranges that house millions of fungal spores. When removing mummies, try to disturb them as little as possible, or cover them with a plastic bag before removing them from the tree. If a citrus tree shows signs of chlorosis (yellowing) on older leaves, it may indicate a nitrogen deficiency. Interveinal (between leaf veins) chlorosis usually means a micronutrient, such as iron or manganese, is needed. Our soil tends to be very low on iron, but you can’t know for sure without a soil test. After the danger of frost has (nearly) completely passed, on March 15th, give citrus trees a good pruning. Just be sure to keep a look out for nests. It’s that time of year!
Another common March task is to inspect and repair sprinklers, drip systems, and water collection systems. How do you know if you have an irrigation leak? It can be difficult to spot, especially if it is small. The most common indication is an area that gets and stays wet longer than everywhere else. Sprinklers should be aimed so that they do not hit tree trunks, walkways, driveways, or sidewalks. The former can cause fungal diseases and the latter creates wasteful urban drool.
March is also a good time to prune out dead branches and twigs from fruit and nut trees and ornamental trees and shrubs. It is easier to see the structure of each plant before it is covered with leaves.
If your roses haven’t already started producing leaves and blooms the way mine have, March is a good time to prune them for better airflow and structure. You can also start feeding roses in March, and you may need to spray for blackspot. Blackspot is a fungal disease that loves moisture. As dew collects on rose leaves, the fungus reproduces astronomically. You can use neem oil or baking soda with horticultural oil. Personally, I use a large fan on my roses in the early morning to speed evaporation of the dew. It seems to work well.
March is an excellent time to start planting your summer garden. In the Bay Area, you can still direct sow many cool weather crops, such as beets, broccoli, cabbage, carrots, cauliflower, chard, lettuces, spinach, bok choy, fennel, kale, mustard greens, parsnips, and turnips. And it's not too late to install that asparagus bed! March is an excellent time to add cilantro, dill, and parsley to your garden, but wait for warmer temperatures before planting basil. Potatoes and radishes can be planted now, and you can start tomatoes and peppers in pots, but only if you can protect them from nighttime cold. Otherwise, wait for April, when the serious planting begins! As you dedicate seeds to a specific location, make sure to read the seed package labels for things like mature size, thinning requirements, and sunlight needs, and be sure to use plant markers!
Slugs & snails
Our warming temperatures and moisture work together to create the perfect habitat for slugs and snails. These mollusks can devastate seedling in a single night, so be prepared. I urge you to follow the link to slugs and snails to learn more about the specific ingredients in different bait products. They are not created equally, and some can harm pets. Choose accordingly.
Walk through your garden in March and you are sure to see weeds coming up in every location imaginable (and a few unimaginable places!). Your Number One March garden task is to pull weeds. Since some weeds can go to seed in as little as a week, now is the time to yank them from the earth. Recent rains and busy worms have made it easier to remove weeds, roots and all, by softening the soil. Wait until later in the season and the ground will be hard and thousands of seeds will already be sown. Healthy weeds make great additions to the compost pile. Personally, I feed them to my chickens.
Enjoy the early blossoms!
We sever that which has passed
As new growth begins
Recent rain has saturated the ground and longer days are coaxing new shoots to emerge. This is the stuff of February gardens in the Bay Area.
Bare Root Trees
There is still time to plant bare root trees. Many of these plants have been sitting in nurseries for a few weeks. Soak them in a bucket of water for several hours after trimming off any damaged bits. Dig a hole that is shallow and wide. Spread the roots out horizontally for the best growth. Be sure that the crown is a few inches above the ground. The crown is where the trunk meets the roots. As the ground settles, you don’t want to risk Crown Rot. Water regularly, unless it’s raining. Avoid fertilizing until 6-8” of new growth appears. Only provide tree supports if absolutely necessary.
Harvesting citrus fruit is a common February garden chore. Citrus trees tend to produce heavily every other year and February is normally harvest time. If you don’t harvest your oranges, other things will! Squirrels, snails and rats can make a mess if fruit isn’t harvested. Try making Orange Marmalade!
Rain also creates countless habitats for mosquitoes. Mosquitoes are a vector species that can carry the Zika virus, dengue, yellow fever, West Nile virus and many other nasty conditions. Walk through the garden to look for potential mosquito habitats. They only need about one tablespoon of stagnant water to start reproducing.
Peppers & Tomatoes
To jumpstart a garden, one February garden chore is to start peppers and tomatoes indoors. Hot peppers, in particular, need a long growing season to develop the best flavors. Seed heating mats, designed for seed starting, can keep the peppers warm enough to germinate. As they grow, transplant seedlings into larger pots until it is warm enough to move them outside.
If it didn’t get done in January, you can still improve the structure and productivity of fruit and nut trees for the upcoming growing season. By pruning unwanted branches in February, trees will put all their energy into what’s left. Remove drooping (decurrent), crossing, or diseased branches. For better fuchsia and hydrangea blooms this summer, remove any frost damaged tissue now. Since both species bloom on new growth, cut back some of the longer branches. Leave two or three leaf buds below the cut. This will promote lateral growth and more flowers.
Sticky barriers prevent ants and other pests from crawling up the trunks of trees, roses and shrubs. As temperatures rise, ants, aphids (pictured above, on broccoli) and other pests become more active and destructive. Apply tape around the trunk and slather the tape with whichever sticky barrier substance you opt to use. This can significantly reduce pest infestations. It’s one February garden chore I never skip!
Lawns may look green, but is it the right kind of green? Weeds grow more quickly than many garden plants. Take a look at what it is really growing there. This is a great time to pull weeds - before they go to seed. The ground is moist, making it easier to pull them up by the roots. Plus, the disruption provides loosened soil for the spreading roots of more desirable grass species. Pull weeds from around perennial plants, as well. They will need all the nutrients they can get for spring growth. Pulling weeds now is one of the most productive February garden chores you can do.
February is the perfect time to encourage worms in the garden. Worms will do more good than pretty much everything else. Worms aerate the soil, break down organic material, and their castings are full of valuable nutrients. Spreading rich compost or mulch around the garden is often the only thing needed to encourage worms to make your garden their home.
So, put on your sweater and get out there in the garden!
Frosted lawns and trees
Cracking crystals in birdbaths
Hunker down in sleep
As holiday decorations are put away and life returns to a chilly normal, January provides some surprising opportunities to benefit your garden with little effort on your part.
If you are like me and enjoy the flavor of fresh asparagus in the spring, this is the time to plant. Before planting asparagus crowns, be sure to select a long term site. My mother discovered a patch of asparagus on her Upstate New York property that had been growing continuously for nearly 100 years! Your asparagus plants will need 2-3 years to get established, but then you will be set for a lifetime of delicious spring stalks that taste better than anything you can find in a supermarket. To plant asparagus, dig trenches that are 8-10 inches deep. Lay out the crowns at 18” intervals and cover with 2-3” of soil and compost. As the plants start to grow, cover them with more soil and compost until the trenches are filled.
Bare root trees
January is also a good time to plant bare root fruit trees. Bare root trees should be planted as soon as they arrive to avoid letting them dry out. When shopping for bare root trees, be sure to inspect the root system and reject plants with knotted or diseased roots. If a tree speaks to you and you simply must have it, cut off any damaged or diseased roots with a sharp tool, cleaning between each cut, and cross your fingers. Your tree will need 6-8 hours of direct sunlight each day, so select a site accordingly. You will need to dig a hole that is two times the width of the root spread, but no deeper than the roots themselves. Be sure to keep any graft unions 2-4” above ground to avoid crown rot. Fill the hole with soil and aged compost and be sure to avoid air pockets that will dry out the young root system. Water regularly (unless it rains) until the roots are established. Contrary to popular belief, there is no need to add special soil amendments to the bottom of the hole before planting.
If you decorated a Christmas tree this past year, rather than kicking it to the curb, now is the time to remove all the lights, decorations and tinsel, and put it to work in your garden. If you have a wild area, you can lay the tree down and let nature do all the work. Initially, your tree will provide shelter for small birds. [I once had a goldfinch escape a hawk for 40 minutes, hopping around the interior of my discarded tree. The hawk finally gave up and the goldfinch survived.] If you feel energetic or want to burn off some of those holiday calories, you can cut the branches from your tree and use them as mulch. Pine needles and twigs decompose very slowly, but they will eventually add their valuable nutrients and improve soil structure. Larger branches and the trunk will take longer to decompose, but they are worth the wait.
January is also the time to start monitoring your citrus trees for ripe fruit and mummies. Mummies are diseased fruits that have become shriveled and/or moldy. Remove these disease carriers as soon as they are seen. You will know your oranges are ripe when they taste good. Looks can be deceiving, so you simply need to pick one that looks ripe and have a taste! The variety of orange makes a big difference in ripening time. The big Navel oranges come ready first, from November to June, while the thinner skinned Valencia oranges should be harvested from February through October. You can leave oranges on the tree for a surprisingly long time. Ripe fruit will feel heavy in your hand but may not pull away from the tree easily. Oranges do not continue to ripen after they are picked, so don't be in a hurry.
While the colder temperatures may have slowed the rate at which your compost pile breaks down, you can still keep adding to it from your kitchen and yard scraps. This goldmine of nutrients provides countless benefits to your soil and the environment. Just remember to turn it occasionally. You may also want to protect the pile from leaching rain with a tarp (I use my plastic kiddie pool, since the dogs have no need of it in winter).
January is also the time when seed and plant catalogs start arriving in the mail. Rather than going hog wild and buying everything that looks good in the photos, use the enclosed plant information to determine which plants will actually thrive in your microclimate, provide food you will eat and plants you will enjoy caring for in the coming spring and summer months.
If you have established trees and roses, January is an excellent time for pruning. The only exception is apricot, which must be pruned in summer to avoid eutypa dieback. Each species of tree has characteristics that make different methods of pruning more effective than others. To learn more, visit the UCANR site. This is also the time to start collecting scions for grafting. Sonoma County Master Gardeners provide an excellent resource that explains how to save scion wood.
While most pests are gone or dormant in winter, you can reduce the likelihood of spring soft scale infestations by spraying your trees and shrubs with horticultural oil now.
In most places, January soil is best left alone. Wet or frozen, this is not the time to be digging. Your plants and soil will benefit from mulch, however. Mulch holds the day’s warmth and improves the soil for spring plantings and new growth.
January is also the perfect time to clean, repair, and sharpen your garden tools. Santa Clara County Master Gardeners provide an excellent video about how to sharpen pruning tools. It is much easier than you might think and you will be amazed at how much easier it is to work in the garden! This is also a good time to clean your pots in preparation for spring. Be sure to wash all pots and tools in a solution of 1 part bleach and 9 parts water to prevent the spread of disease.
Start your gardening year with clean, sharpened tools, a little preventive work, and a plan for a successful growing season! Happy New Year!
Time for rest, sweet December
Sever ties with old
Making room for new
December is filled with holiday functions, family travel, and (hopefully) some much needed rain. The Bay Area is still struggling with drought, even though the greening hills seem to say otherwise. With all the hustle and bustle of the holiday season, it is easy to put aside garden tasks for another time. We need to rest when we can, too, just as our garden plants do each winter. But December is an excellent time to prevent future problems in the landscape. With just a little bit of effort now, we can have bigger harvests and healthier plants next summer.
Bare root planting
December is an excellent time to install bare root plants in the Bay Area. Any of these bare root plants can be planted in December:
Cool weather crops
Occasional rains will help keep compost piles moist, but remember to turn your compost pile to incorporate the oxygen needed by helpful microorganisms. You may need to cover your compost pile during heavy rains to prevent losing all those valuable nutrients.
Divide & cut perennials & bulbs
Some plants will perform better next year by being cut back or divided in December. Dividing plants means digging them up and separating clusters of roots or bulbs, and replanting them with room to expand. Chrysanthemums, alum root, seaside daisy, yerba buena, purple needle grass, daylilies, Douglas iris, deer grass, Idaho fescue, purple needle grass, and many bulbs are just a few of the plants that benefit from this treatment.
Santa Clara County’s first and last frost dates are November 15 and March 15. For plants that may be damaged by frost, you can protect them by draping sheets, tarps, or other light fabric over and around them. Do not allow the fabric to touch the plants. Umbrellas and old fashioned (not LED) Christmas lights can also provide some protection. Potted plants can be brought indoors or closer to protective structures. And be sure to water frost sensitive plants. Damp soil holds more heat than dry soil. Also, mulch can stabilize below ground temperatures. If frost damage does occur, resist the urge to clip away the damaged bits - they create a barrier against further frost damage. If it looks really hideous, leave it covered.
Garden bed care
As many annuals end their lifecycle, be sure to remove them from the garden bed. Adding plant debris to the compost pile not only creates nutrient rich compost, but it interrupts the lifecycle of many garden pests and diseases. If plant materials are already diseased, they should be thrown in the trash.
Holiday plant care
Poinsettias, Christmas trees, Christmas cactus, amaryllis, and many other holiday plants find their way into our homes in December. Most of these plants prefer cooler temperatures and higher humidity than our homes can provide. Keeping plants away from heater vents and misting them occasionally will help. Also, avoid overwatering.
Winter irrigation is largely dependent on the weather. December is a good time to turn off the sprinklers and monitor the soil. Cooler temperatures mean slow growth but some water is still needed. Also, if an area becomes saturated, avoid walking on it. This prevents soil compaction.
Happy holidays, fellow gardeners!