Glyphosate is an herbicide. It is the active ingredient in Roundup and other broadleaf weed and grass killers. Scientific research has shown that glyphosate may be partially responsible for the global die-off of honey bees.

My soapbox

Before we begin learning about this litigious herbicide, let me tell you from the gate that I do not use it in any form. I practice sustainable, integrated pest management (IPM) and organic gardening.
​
The chemistry of glyphosate

Glyphosate is a broad-spectrum, systemic herbicide, which means it is absorbed by and kills the plants it touches. It does this by blocking an enzyme pathway called the shikimic acid pathway. [It gets this unique name from the Japanese shikimi flower, which was part of the initial discovery in the 1800s.] When the shikimate pathway in many organisms is blocked, they die.

Glyphosate in the environment

Glyphosate is the world’s most-used pesticide, with over 700,000 tons produced annually. As a substance, glyphosate molecules bind tightly to soil. While this means they are less likely to end up in groundwater as motor oil, it can cause a different type of pollution. Depending on soil type and weather conditions, glyphosate may remain in the soil for six months or more. 

Soil bacteria break down glyphosate, but I have to wonder about the chemicals those bacteria poop out afterward. Maybe it’s just me. Some studies have found that carrots and lettuce plants absorb glyphosate months after spraying. Many glyphosate products also contain other toxic ingredients.

Glyphosate and GMOs

Glyphosate use walks hand-in-hand with genetically modified plant development. GMOs are resistant to glyphosate and other weed-killing chemicals by design, allowing farmers to grow more food for our ever-increasing global population. It certainly has its appeal. It’s so simple—Aim, squirt, done. No more weeds. But at what cost?

Glyphosate and overspray

If you (or your neighbor) use a glyphosate product, be aware of the overspray risk. Since none of us is perfect, and breezes happen, these chemicals can travel on the wind to where they are not welcome. That delicate, well-loved exotic, handed down from your great-grandmother, is just as vulnerable to death by glyphosate as the dandelions. Also, since glyphosate indiscriminately kills all the plants it touches, many plants important to local biodiversity are being lost to this herbicide. We do not yet know the full extent of that domino effect.

Glyphosate and bees

Beekeepers have long suspected that glyphosate is partly responsible for the recent decline in global bee populations. [Did you know that China now must hand-pollinate their apple and pear trees because there are not enough bees?] Research from the University of Texas at Austin shows that glyphosate kills beneficial bacteria in a honey bee’s gut, making the bees more susceptible to infection. [Maybe we need to start feeding our bees probiotics? I’m guessing.] 

Glyphosate use

Glyphosate first came on the market in 1974. It provided an easy way to kill weeds with just a squirt. Commercial farms, railroad companies, and city parks all use glyphosate. According to the National Pesticide Information Center, farmers use one form of glyphosate to regulate plant growth and ripen fruit. It’s convenient, but not what I want in or on my food.

More than 750 products on American shelves contain glyphosate, including Roundup, Bonide KleenUp Grass and Weed Killer, and Kleeraway Grass & Weed Killer. According to the Environmental Working Group (EWG), glyphosate is also in many oat products on grocery store shelves. This organization has successfully gotten many companies to reduce the amount of glyphosates in our food. You can read more here. Drugwatch also has more information.

The FDA is aware of glyphosate in our food but has failed to release its findings publicly. [Makes me wonder what we are paying taxes for...] Glyphosate may also be involved in Parkinson’s and Alzheimer’s diseases and may cause cancer.

Herbicide safety

​As with any herbicide, always follow the package directions EXACTLY and COMPLETELY. It is not a time to be careless. You can harm other plants with overspray or expose yourself to dangerous chemicals. It can occur by breathing it in during the application process, eating or smoking after applying it, if you don’t wash your hands, or by touching plants still wet from the spray. If exposure occurs, follow the first aid directions on the product label. For more information about risks and treatments, contact the Poison Control Center at 1-800-222-1222. Pets are also susceptible to herbicide poisoning.

The truth about nuts may surprise you.

While you probably already know that peanuts are not nuts (they’re legumes), many of the other foods you have come to know as nuts are not true nuts at all. Let’s begin by learning the botanical definition of nuts.

True nuts are hard-shelled, inedible pods that hold both the fruit and the seed of a plant. These pods do not open of their own accord, which means they are indehiscent. The pod, or shell, of a nut is made from the ovary wall, which hardens over time. Hazelnuts, chestnuts, and acorns are true nuts. So are kola nuts, which gives “cola” soft drinks their signature flavor.

A nut is not a nut when it is a fruit seed. Fruit seeds can be angiosperm, drupe, or gymnosperm seeds:

• Gymnosperm seeds, such as pine nuts and ginkgo nuts, are not true nuts.
• Angiosperm, or flowering plants that produce seeds within a carpel, include macadamia nuts, Brazil nuts, peanuts, and soybeans.
• Drupes, such as peaches and cherries, are a type of angiosperm which have hard-shelled pods that hold a seed, but their fruit is on the outside. Almonds, cashews, pecans, pistachios, walnuts, coffee beans, and coconuts are all drupes.

These not-nut nuts are commonly referred to as culinary nuts.

[Did you know that cashews are the seeds of an accessory fruit, which means they share characteristics with strawberries and poison ivy. Isn’t botany amazing?]

Of course, you can call any of these delicious morsels "nuts" whenever you want to. True nut or culinary nut, many of these yummy snacks find their way into our gardens and foodscapes. Which ones are you growing?

Soil moisture

Water, plants, and soil perform an intricate dance. The soil has spaces, called macropores and micropores, that allow air, roots, and water to move through. The water molecules in the soil are strongly attracted to each other, using surface tension. This is how soil holds onto water, despite the pull of gravity. The amount of water a soil profile can hang onto is called its water holding capacity, or field capacity. When a soil is holding all the water it can, and becomes saturated, any additional water is pulled into the ground water by gravity, or runs off as urban drool, where it eventually is discharged into rivers, lakes, and oceans. At the opposite end of the soil moisture spectrum, a soil can be so dry that it becomes hydrophobic. Hydrophobic soil actively repels water.

​Sponges act the same way. If you have a completely dry sponge, water will tend to run across the top, rather than be absorbed. Once a little water is absorbed, a lot more is pulled into the spaces that make up the majority of a sponge. Finally, if even more water is added, it will simply flow through the sponge.

​Why the wilt?

Plants wilt for several different reasons. Bacteria or fungi may be blocking the xylem, there may be too much salt in the soil, ice damage may have occurred, or because the soil has reached the wilting point. When plants do not contain enough water, plant cells cannot remain plumped up, or turgid. As water becomes less available, cells shrink and become floppy. [Tree trunks do not get floppy because they contain lignin. Unlike cellulose, which is a sugar-based material, lignin is alcohol-based, but we will discuss lignin another day.] The problem with wilting is that there is a point of no return. This is a soil’s permanent wilting point.

Permanent wilting point

Permanent wilting point is death for plants. If a soil moisture rating reaches or surpasses the permanent wilting point, it doesn’t matter how much water you add later, the plant will die. This occurs more often with containerized plants, but it can happen anywhere.

Soil texture plays a big role in how much soil moisture is not enough to keep a plant alive. This is due to the soil’s ability to hold the water so tightly that plant roots cannot suck it in. The permanent wilting point occurs at 15 to 20% for clay soil, 10 to 15% in loamy soil, and at 5 to 10% in sandy soil. 

You can monitor soil moisture using an inexpensive moisture meter.

How to grow millet

Millet seeds can be broadcast by hand over an area and raked in, or you can drill holes that are 1 to 4” deep for the seeds. [Did I mention that millet is rugged?] Once plants are established, they will readily self-seed the area, year after year. Because of millet’s high carbon to nitrogen (C:N) ratio, it is best balanced with low C:N plants, such as legumes, in crop rotation.
​
Millet pests and diseases

Generally speaking, millet has few pests, other than Bagrada bugs and crane flies. Millet diseases lean toward the fungal variety, with blast, leaf spot, downy mildews, ergot, rust, Johnson spot, smut, and blight causing the most problems. Simply provide good drainage and reasonable irrigation to avoid most of these diseases.

Millet, it’s not just for the birds (though you may need to protect your crop with netting or row covers, if you want any left to harvest). You can have it for breakfast, use it to increase biodiversity in your yard, or, if you’re feeling adventurous, millet can even be used to make alcoholic beverages!

A few insects that migrate

Our gardens are impacted by several different migrating insects. A few of these pests (and their favored foods) include:

• Western boxelder bugs (Boisea rubrolineata) - almond, apple, cherry, peach, pear, and plum tree fruit, grapes, and ash, elder, and maple trees
• False chinch bugs (Nysius raphanus) - tomatoes
• Leaf-footed bugs (Leptoglossus sp.) - almonds, pistachios, pomegranates, and tomatoes
• Lesion nematodes (Pratylenchus vulnus) - cucurbit, grape, olive, and onion roots
• Lygus bugs (Lygus hesperus) - peaches, pears, pistachio, strawberries; they also carry fireblight and cause catfacing on tomatoes
• Migratory grasshoppers (Melanoplus sanguinipes)
• Stink bugs - almonds, apples, peaches, pistachios, and tomatoes; they also eat seeds, grain, vegetables, ornamental plants, legumes, weeds, and tree leaves

You can join the citizen science movement related to insect migrations by reporting your sightings to The Big Bug Hunt. Your information will be added to countless other sightings to generate ever more reliable prediction models. This can help you protect your plants better, faster, and with less effort, using row covers.​

Plant nutrition

There are 16 chemical elements critical to plant health. Depending on how much is needed, they are labeled as micronutrients (tiny amounts) or macronutrients (large amounts). Macronutrients are further divided between primary and secondary nutrients. Primary nutrients are the NPK of fertilizer bags. Plants use nitrogen, phosphorus, and potassium more than any other plant food, which is why they are the ones most often needing replacement. They are the rice and beans of a plant’s diet. Secondary nutrients, calcium, magnesium, and sulfur, rarely need to be supplemented, but they are very important to plant health. Micronutrients include boron, copper, iron, chloride, manganese, molybdenum, and zinc. [These used to be called trace elements.]

If you count up all those nutrients, you will only find 13. That is because plants also have non-mineral nutrients. These non-mineral nutrients are hydrogen, oxygen, and carbon. All of these nutrients work together to provide your plants with the energy and materials needed to grow. Some of those nutrients are mobile, while others are immobile.

Nutrient mobility

Highly mobile nutrients go where they are needed within a plant. Nitrogen, potassium, phosphorus, magnesium, chloride, and molybdenum are all mobile plant nutrients. All the other nutrients are considered immobile because they stay where they were initially placed. Problems with mobile nutrients tend to appear in older leaves, while problems with immobile nutrients are seen in new growth. This is important to know because it can help you narrow down deficiencies and toxicities.

What is in your soil?

Before we take a closer look at each of these important factors to plant health, let me remind you that you cannot know what nutrients are in your soil without a soil test from a reputable lab. I wish those colorful plastic tubes from the store could do the job accurately, but they can’t. Not yet, anyway. Contact a local soil test lab and find out what you are working with. Not knowing the facts can lead to toxic levels of these nutrients, which can backfire. [For a hysterical read about the effects of too much fertilizer, check out Don Mitchell’s Moving/Living/Growing Up Country series.]

Just because your plants are not thriving does not mean they need to be fed. All too often, plant problems are caused by inhospitable soil conditions, unhealthy roots, irrigation problems, pests, or disease.

So, let’s see what each of these nutrients do for your plants:

Primary macronutrients

• Nitrogen (N) is the single most critical plant food. It is part of the chlorophyll used in photosynthesis for rapid leaf growth. Nitrogen is abundant in our atmosphere, but only legumes can convert atmospheric nitrogen into a usable form. Nitrogen can occur in ammonia (more alkaline) or nitrate (more acidic) forms.
• Phosphorus (P) stimulates root, fruit, and flower growth, and is used in photosynthesis.
• Potassium (K) is used in stem and cell growth, to fight disease, and improve fruit quality.

Secondary Macronutrients

• Calcium (Ca) is used to build cell walls, and to move other nutrients around.
• Magnesium (Mg) is essential for photosynthesis and it activates plant enzymes.
• Sulphur (S) is used to create amino acids for root and seed production.

Micronutrients

• Boron (B) is used to make cell walls, to reproduce, and in sugar and carbohydrate production.
• Chlorine (Cl) aids plant metabolism during photosynthesis. It is necessary for osmosis and fluid balance within plants. Too much chloride (common in areas with hard water) can interfere with nitrogen absorption.
• Cobalt (Co) is used by legumes in nitrogen fixing.
• Copper (Cu) is used to make reproductive enzymes, to metabolize proteins, and to help plant roots eat and breathe.
• Iron (Fe) is essential in the production of chlorophyll and moving electrons around within the plant. Iron is also used in enzyme functions that help your plants absorb many other nutrients.
• Manganese (Mn) activates plant enzymes that breakdown carbohydrates and nitrogen into usable bits.
• Molybdenum (Mo) helps plants use nitrogen by working with certain enzymes.
• Nickel (Ni) is used in nitrogen processing and disease protection.
• Selenium (Se) is believed to stimulate plant growth and to counteract stress, pests, and disease.
• Silicon (Si) is used by plants to build cell walls and to improve plant health and productivity.
• Sodium (Na) is needed at low levels to stimulate growth, maintain water balance, and improve fruit flavor.
• Vanadium (V) is used by some plants as a substitute for molybdenum.
• Zinc (Zn) helps plants breakdown carbohydrates, regulate sugar consumption, and activates enzymes.

Non-mineral nutrients

• Carbon (C) is used by plants as energy, structural building blocks of starches, proteins, and cellulose, and in photosynthesis.
• Hydrogen (H) impacts soil pH and is used in photosynthesis and respiration, and to build sugar molecules.
• Oxygen (O) is used in respiration and, when combined with hydrogen to make water, in building and moving molecules within the plant.

Not enough of a plant nutrient, or too much, can cause problems. The tricky part comes in when the balance of nutrients is out of whack.

Nutrient interactions

A man named Mulder created a chart that shows us the interactions between plant nutrients. While there are limits to the usefulness of this overly simplistic view, it can help you understand what might be happening to your plants.

According to Mulder's Chart, synergistic elements help each other to be absorbed by plants, while antagonistic elements get in each other’s way. Using the chart above, you can see that proper levels of potassium help plants absorb iron and manganese, but too much potassium interferes with a plant’s ability to absorb boron, calcium, magnesium, nitrogen, and phosphorus. This interference can take the form of competition for space on water molecules, or it can alter soil pH, making some nutrients unavailable.

Plant food and soil pH

Soil pH ranges from 0 to 14, with lower numbers indicating acidity and higher numbers indicating alkalinity. Using the chart below, you can see that more nutrients are available, and there is greater microbe activity, when soil pH is between 6.0 and 7.0. Most plants can survive in soil pH from 5.2 to 7.8, but the narrower range allows plants to thrive. This is because the minerals used as food are ions. Ions are atoms and molecules that have a positive or negative charge. These cations and anions, respectively, attach themselves to water molecules and are pulled into the plant by root hairs. The wrong soil pH can cut your plants off from a bounty of nutrients.

Soil is given a cation exchange capacity rating to describe its ability to hold nutrients. [Did you know that root hairs knock cations (unbalanced atoms or molecules) loose with a hydrogen canon? Stay tuned for more on that!]

How to feed your plants

While there is no chemical difference between nitrogen from compost and nitrogen formulated in a lab, I prefer feeding my plants with composted yard and kitchen scraps and chicken bedding. Not only does this mix have excellent nutrients, it also improves soil structure. If you decide fertilizer really is necessary: READ THE BAG. Seriously. Federal law requires that important information is printed on the container and for good reason. Follow directions carefully and wash your hands when you’re done.

What are your plants hungry for?

​Some soils can hold a lot of water and other soils hold very little. Since many plant nutrients are held in suspension (float around in water), and nearly all plants need water to stay upright and alive, the amount of water a soil can hold has a huge impact on plant health.

The water holding capacity of a soil also has a big impact on how often you need to water and feed your plants. Let’s find out what your soil’s water holding capacity is, and how it impacts your garden.

Water for plants

Not all the water held by a soil can be reached by plants. Sometimes it is too deep. In other cases, the water may be protected by a layer of rock. The amount of water in the soil that plants can reach and use is called plant available water. If a plant cannot reach enough soil water, it will hit a wilting point. At the opposite end of the moisture spectrum, field capacity (or drained upper limit) refers to the total amount of water a soil profile can hold. Anything beyond that saturation amount leaches into groundwater, or runs off, as urban drool.

Soil texture

The first step to calculating your soil’s water holding capacity is to identify its texture. Soil texture refers to the percentage of sand, silt, and clay that makes up your soil. You may be surprised to learn that those words only refer to particle size, and not to any chemical properties. Very large particles (sand) have very large spaces, called macropores and micropores, between the particles, while clay particles have very tiny spaces.

These spaces allow air, water, nutrients, and roots to move through the soil. In the case of sand, the large macropores and micropores allow water to slip away quickly, carrying nutrients, pesticides, and other materials away with it. Loam, having smaller macropores and micropores than sand, slows the leaching of water, which increases that soil’s water holding capacity. Clay, with the tiniest macropores and micropores of all, has the highest water holding capacity, being able to hold up to six times the amount of water held by sand, but that ability comes at a price. Roots, air, and nutrients also have a difficult time moving through clay soil.

​Soil structure

The way the soil particles clump together into aggregates is called soil structure. There are eight types of soil structure, based on size, shape, and stability. Different soil structures can hold on to different quantities of water (inches per foot):

• coarse sand - 0.50
• fine sand - 0.75
• loamy sand -  1.00
• fine loamy sand - 1.25-2.00
• silt loam - 1.75-2.00
• silty clay loam - 2.00
• clay loam - 2.00
• heavy clay - 1.75-2.00

If you look closely at your soil with a hand lens or a simple microscope, you will be able to see these different shapes. The way the shapes create spaces within the soil impacts its water holding capacity. Soil structure also helps explain soil compaction. Some shapes and sizes, clay in particular, are far more likely to become compacted or have drainage issues

What is your soil’s water holding capacity?

You can conduct an experiment to see what your soil’s water holding capacity is, using simple household items. First, collect a soil sample from your garden. You may want to collect several different samples, for comparison. [Just be sure to label everything clearly!] Each sample should be the same size - 1/2 cup should work well. Then, place a paper coffee filter in a funnel, and put your sample in the coffee filter. Place the funnel into a large cup. Next, very, very slowly, pour 2 cups of water into the soil. Be sure to move the stream around, wetting all of the soil. Wait five minutes. Then, measure the water that flowed through the soil, into the cup. The difference between what you started with (2 cups) and what you ended up with will tell you how much water that amount of soil can hold.

Improving water holding capacity

Too much water and too little water are both bad for plants. Nutrient loss, leaching, and water pollution are also part of the equation. Adding aged compost to your soil improves its water holding capacity, along with its structure, texture, and microbe biodiversity. As organic material decomposes, a wide variety of spaces, minerals, and plant nutrients become available, allowing roots to reach the food and water they need, without struggling in a pit of mud.

Soil texture is a measurement of the relative proportions of the sand, silt, and clay minerals found in a soil sample. Each of these words actually refers to the particle size of these soil separates, and not to any particular chemical property:

• sand - 1/12 to 1/500 inch, or greater than 0.05 mm
• silt - 1/500  to 1/22,500 inch, or 0.05 mm to 0.002 mm
• clay - less than 1/12,500 inch, or less than 0.002 mm [smaller than most bacteria]

To put these numbers into perspective, imagine that a dime is a particle of clay. If that were true, silt would be about the size of a softball and a grain of sand would be the size of a bicycle wheel. Of course, there are no bicycle wheel sized grains of sand, but they can be seen with the naked eye. Silt particles can be seen with a standard, classroom microscope. To actually see clay particles, you would need to use an electron microscope, they are so small! Also, while most soil particles tend to be spherical, clay forms plates that generate up to 100,000 times more surface area. These means that there are many more potential points of attachment for nearby nutrients and water molecules. 

Soil texture classifications

In the U.S., we use 12 different classifications to talk about soil texture. Each class has specific characteristics based on its feel, its tendency to crumble, and its likelihood of leaving a ‘stain’ behind on your fingers when handled:

• sand - gritty, unable to retain shape, no stain
• loamy sand - gritty, crumbles easily, leaves slight stain
• sandy loam - moderately gritty, clods come apart easily, definite stain
• loam - somewhat gritty, clods moderately difficult to break, forms a ball when wet; stains
• silt loam - hard clods, dust feels powdery, mud feels buttery, stains
• silt - feels soapy when wet, stains
• sandy clay loam - hard clods, slightly gritty feel when wet, stains
• clay loam - hard clods, slightly gritty feel when wet, stains
• silty clay loam - hard clods, feels smooth, stains
• sandy clay 
• silty clay
• clay - ultra hard clods, sticky when wet, stains

You may also hear someone talk about soil that is fine textured or coarse textured. Finely textured soil contains more clay, while coarsely textured soil holds more sand. Soil texture is not the same thing as soil structure. Soil structure refers to the way minerals, air, water, microbes, and everything else is arranged into clumps, called aggregates. 

Soil texture and drainage

The large and small spaces between these particles are called macropores and micropores, respectively. These spaces are what allow water, air, nutrients, and roots to move through the soil. In most cases, those spaces are similar in size to the particles they are around. Since water molecules tend to stick better to smaller particles, such as clay, and the micropores are smaller, clay has a far higher nutrient and water holding capacity than loam or sand. Clay is also more prone to drainage and compaction problems. Clay is also harder for roots (and shovels) to move through. The larger macropores and bigger particle size of sandy soils make leaching and nutrient loss more common problems. Erosion is another factor to consider when it comes to soil texture. Heavy sand and sticky clay are less likely to blow or wash away, while loam is more vulnerable to erosion.

Soil texture and nutrient retention

The nutrients used by plants are ions of specific elements. Ions are atoms or molecules that have either a positive or negative charge, due to the addition or loss of an electron. Cations, such as calcium and potassium, are positively charged and attracted to negatively charged soil particles. Anions, such as phosphorus and sulfur, are just the opposite. The ability of a soil to hold onto a positively charged mineral ion is known as its cation exchange capacity. Organic material and clay tend to have negative charges, while water and sand tend to be positively charged.

How to identify your soil’s texture

Use these steps to determine your soil’s texture:

1. Collect 2 cups of soil, removing all rocks, roots, and debris.
2. Spread soil out on a newspaper to dry, crushing all clumps and clods.
3. Finely pulverize the soil sample after it is dry.
4. Shake the dried, pulverized soil through the smallest screen you can find. (Labs use 2 mm. This soil residue is called fine earth.)
5. Fill a tall, slender jar 1/4 full of the sifted soil.
6. Add water until it is 3/4 full.
7. Put on a tight fitting lid and shake hard for 10 to 15 minutes. [Some people use a blender for this, but their margaritas may end up being a tad gritty…]
8. Place the jar in a location where it will not be disturbed for 2 or 3 days.
9. After only one minute, you can mark the sand level on your jar.
10. After two hours, you can mark the silt level on the jar.
11. Once the water clears, which may take 1 to 3 days, or weeks, you can mark the clay level.
12. Using a ruler, measure the thickness of each layer and the total sample.
13. Calculate the percentage of sand, silt, and clay by dividing each individual layer by the total sample depth.
14. Use the soil texture triangle (below) to find where they three percentages meet to identify your soil texture.

​For example, a 10” sample has 1” sand (10%), 7” silt (70%) and 2” (20%) clay:

• Starting at the 20% point for clay, draw a horizontal line across the triangle.
• Starting at the 10% point on the edge labeled sand, draw a line that is parallel to the right hand side of the triangle.
• Starting at the 70% point on the side labeled silt, draw a line that is parallel to the left hand side of the triangle.
• The three lines meet within the area marked as silty loam.

Creating better soil texture

Ideally, your soil will be 50% macropores and micropores (containing 50% air and 50% water), 2 to 5% organic material (more is better), and 45 to 48% minerals. In a perfect growing medium, those minerals would be 40% sand, 40% silt, and 20% clay.

Rather than trying potentially disastrous quick fixes* to improve your soil’s texture, adding small amounts of organic material, such as aged compost, over a long period of time, will improve your soil’s ability to retain water and nutrients, while still allowing air, water, and roots the spaces they need to move freely.

The purpose of prickles

The most obvious purpose of prickles is to make plants less palatable to herbivores. Chewing on a stem covered with prickles can’t be very appealing. In extreme cases, such as the silk floss tree, the entire trunk is covered with massive prickles. I suppose that’s the level of protection needed in rural South America.

While prickles are generally meant to keep herbivores away, most species specific pollinators have learned to maneuver around the prickles without too much trouble. Prickles can also provide limited amounts of shade or insulation from temperature extremes.

A rose by any other pokey bit

Everyone calls the sharp bits on rose stems thorns, but they are actually prickles. One easy way to tell if a protuberance is a prickle, thorn, or spine, is by how easy it is to remove. Spines and thorns contain vascular bundles, but prickles do not. ​

This is why it is so easy to flick a rose thorn from its stem, while trying the same trick on your orange tree won’t work. Orange tree thorns have added strength from the phloem and xylem, carrying water and nutrients into the pointy protuberance. Thorns do not have that type of attachment, so they are easier to remove.

So, now you know the difference between thorns and prickles.

Predaceous ground beetle life cycle

Eggs are laid in moist soil. When they hatch, larvae that look similar to earwigs emerge. These larvae feed voraciously on slugs and snails, and many bothersome soil dwelling insect larvae and pupa. These pest insects include masked chafers, caterpillars, grubs, tussock moth and gypsy moth larvae, other beetles, and maggots.

​While predaceous ground beetles will occasionally eat seeds and organic litter, they prefer meat to vegetables. In fact, adult Calosoma sycophanta (affectionately known as caterpillar killers) eat several hundred caterpillars in their 2 to 4 year lifespan, and their larvae eat up to 50 caterpillars before transforming into adults! While not exactly predaceous, Lebia grandis loves to feed on potato beetle eggs and larvae.

So, the next time you see a black beetle running across the patio, look for fat legs and eyebrow ridges before squashing it!

Plants that are struggling need more fertilizer, right?

It makes sense. Your plants were doing fine, growing and thriving. Then, they started to decline. Leaves lost their color and fell off, stems lost their vigor, and flowers started looking like pale comparisons of their former selves. So, you add fertilizer and the plants look better. For a while. Then the decline returns. You add more fertilizer. And the cycle continues.

While you may think you are feeding your plants a healthy diet, what is more likely to be happening is toxic levels of some nutrients are building up in the soil, causing more complex problems. Excluding disease, insect attack, or improper soil pH, adding more fertilizer makes sense, on the surface. Except when it doesn’t, because sometimes that’s the last thing you should do. While there are certainly cases in which adding an all-purpose (hopefully organic) fertilizer is a good idea, more often than not, nutrient-based problems are more about imbalances and nutrient mobility.

Nutrient imbalances

Before we look at nutrient mobility, we need to understand a little bit about nutrient imbalances. In technical terms, this is called the cation exchange capacity. Put simply, cation exchange capacity (CEC) is a measurement of how many positively charged minerals can be held by the surface of a soil particle. Clay and organic material tends to be negatively charged, while many plant nutrients are positively charged. Mineral ions that are negatively charged are held in suspension, in water. These charged ions act like magnets. If the electrical charges are out of balance, plants cannot absorb the nutrients they need. This is why adding even more of an unnecessary nutrient can make matters worse, rather than better. In some cases, nutrients may already be inside your plant, but not where they are needed. This is where nutrient mobility comes in.

Plant nutrients and mobility

Plants absorb fourteen mineral nutrients from the soil. These nutrients are divided into macronutrients and micronutrients. Plants need large amounts of the macronutrients and small amounts of the micronutrients. Don’t be fooled, however. Just because a small amount is needed, doesn’t mean it is unimportant. As in the case of iron, insufficient levels can cripple a plant’s ability to absorb and use many other nutrients.

​Mobile nutrients

When a nutrient is considered mobile, it moves around inside a plant easily. Nitrogen is a highly mobile nutrient. Nitrogen deficiencies can be seen when nitrogen is pulled from older leaves, causing chlorosis (yellowing), to feed newer leaves. Other highly mobile plant nutrients include phosphorus, potassium, magnesium, chlorine, molybdenum, and nickel. When any of these nutrients become deficient, the symptoms will appear in older growth first.

Immobile nutrients

Other nutrients are not easily moved once they are incorporated into a plant. In most cases, these nutrients stay where they are first dropped off, usually at growing points. This is great for as long as there is a steady supply of those nutrients. It takes a lot of water to move them around inside a plant. This is why blossom end rot isn’t really caused by a simple calcium deficiency. Instead, it is caused by insufficient calcium and insufficient water, which is needed by the plant to move the calcium where it is needed when it is initially absorbed. Other immobile nutrients include sulfur, boron, copper, iron, manganese, and zinc. Deficiencies of immobile nutrients are more likely to appear in newer growth.

What nutrients are in your soil?

I’ve said it before and I’ll say it again: you don’t know what is in your soil without a soil test from a reputable, local lab. I wish I could say that those cute, over-the-counter soil tests were effective, but they aren’t. Not yet, anyway. Find a soil test lab on your side of the Rocky Mountains and send them a sample. That is the ONLY way to know what nutrients are available to your plants. 

What are you feeding your plants?

How to grow ajwain

Ajwain is generally grown from seeds, though you can use cuttings. To grow from seed, plant 1/4-inch deep in rich, potting soil, or scatter on top of the soil. Use a mister to water, to avoid washing all the seeds into a corner of the pot. Mist daily for a week or two, until germination occurs. Once the first true leaves emerge, you can transplant the seedling into a larger container. [I couldn't find any free images of ajwain plants, so you will have to wait until mine get started...]

To propagate ajwain from cuttings, take stems that are a few inches long and remove all but the upper two sets of leaves. Bury the stem in potting soil, with the leaves exposed ands water regularly. Before you know it, new roots will emerge. Ajwain’s feather-like leaves grow on many branched stems, creating a lovely container plant. Because it is so pungent, most insects are not interested in ajwain plants.

Ajwain prefers partial sun or partial shade. Full sun can be too much for these plants. And keeping the soil moist but not soggy will keep these plants healthy and productive.

If you happen to have a tummy ache, ajwain seeds can help relieve some of that discomfort.

Curly dock description

Curly dock seedlings can be green or tinged with red. Wavy or curled leaves grow in a rosette, close to the ground, while flower stalks, or inflorescences, can reach 3 to 5 feet in height. Flowers are produced in clusters on these stalks. Fruits are triangular achenes, much like buckwheat. Curly dock seeds tend to catch on fur and sweaters, helping spread the species far and wide. Underground, curly dock features a large, forked yellow taproot.

If you’s rather get rid of the curly dock in your garden, limit wet areas. Curly dock loves moisture. Also, be sure to cut off and dispose of seed heads before they mature. Eventually, you will reduce the curly dock population in your garden.

If you happen to get stung by stinging nettles, rub a large curly dock leaf over the area to relieve some of the pain.

Bacterial leaf scorch is a collection of diseases that can affect a wide variety of plants.

Bacterial leaf scorch (BLS), mistakenly known as bacterial leaf spot, is a tricky disease, because it is actually several diseases caused by different strains of a single pathogen. That pathogen, Xylella fastidiosa, causes different diseases in different plants. And sometimes those bacteria strains overlap their feeding habits, making classification and control difficult.

Lifecycle of Xylella fastidiosa

This particular bacterium is what’s called a fastidious mollicute, which means it must live within a plant’s xylem to be able to reproduce. The diseases they cause occur because they get so overcrowded that they block the flow of water and nutrients through the xylem.

Not all plants are negatively affected by this bacterium. Clover, blackberry, goldenrod, and many grasses can host this pathogen, acting as a way station without suffering any consequences. Unfortunately, when a sharpshooter feeds on one of these plants and then moves to your garden, trouble can start.

Symptoms of bacterial leaf scorch
​
Scorch diseases are characterized by the same symptoms you would see as a result of environmental conditions, such as herbicide overspray or too much fertilizer, or other diseases, such as verticillium wilt. Initially, you will see wilting and/or chlorosis. Leaf edges look, well, they look scorched! Then leaves start dropping. Fast. Before you know what happened, the plant dies. Except when it doesn’t, because sometimes it won’t. Scientists are still trying to sort it all out.

Disease vectors

The bacteria that cause scorch diseases are carried into your garden by leafhoppers and spittlebugs. Actually, it’s in their saliva. Sharpshooters are the biggest carriers of the disease, as far as we know. These insect pests have a wide host range of their own. As sapsuckers, every bite they take infects the plant on which they are feeding. Because their host range is so large, they are spreading diseases to plants that have never been exposed before, so they have no defenses in place.

There are no known chemical treatments for scorch diseases, so controlling the disease carriers is your best bet. If the disease appears, remove the infected plant completely and put it in the trash.
​
Mulching and proper irrigation can help your plants protect themselves.

Curly top may sound like a cute little redheaded kid, but it’s a viral disease of many garden plants.

​Curly top host plants

This viral disease can infect watermelon, horseradish, pumpkins, beans,  squash, spinach, melons,
peppers, chickpeas, groundcherries,  tomatoes, and more. Scientists have identified different species of viruses that cause similar symptoms. For lack of better ideas, those viruses are called beet curly top geminivirus (BCTV), beet mild curly top virus (BMCTV), and beet severe curly top virus (BSCTV).

This condition is often fatal in young plants. Infected older plants may only turn yellow. The telltale symptom of curly top occurs when the top of the plant turns into a rosette or tiny bouquet. If any fruit develops, it will taste bad, the skin will be dull rather than shiny, and it will ripen before it reaches full size.

Curly top virus lifecycle

The virus overwinters in annual and perennial weeds. From there, beet leafhoppers (Circulifer tenellus) carry the disease to your garden plants. Symptoms don’t start to appear until long after the leafhoppers are gone. Since they are the disease vector, controlling leafhoppers goes a long way toward preventing this disease. Unfortunately, insecticides are generally not effective against leafhoppers. Leafhoppers have many natural enemies, so make your garden hospitable to beneficial insects. You can do this by avoiding broad-spectrum insecticides, planting a variety of umbellifers, such as dill, carrot, and fennel, and providing a water source.

The symptoms and host plants of curly top look too much like several other viral diseases, such as spotted tomato wilt, to be identified by the casual gardener. Laboratory tests are needed to know for sure. In the case of viral disease, it is simpler to yank the plant and toss it in the trash rather than spreading the infection to other plants.

Legume fruits

Legume fruits, or pulses, are simple dry fruits that are low in fat. They develop from a single carpel and are normally dehiscent, which means they unzip along one edge. These fruits are often called pods, but that isn’t exactly inaccurate. Pulses are only one type of pod. A radish silique and a vanilla capsule are also pods. While peanuts and soybeans are both legumes, they both have a high fat content, they are not considered pulses.

No green pulses

If you harvest peas or beans while they are green, they are not called pulses. They are simply vegetable crops (even though they are fruits). The same is true for legumes harvested specifically for their oil. This is a rule put out by the United Nations’ Food and Agriculture Organization (FAO).

Differences between pulses and cereal grains

Cereal grains, such as rice, wheat, barley, corn, and sorghum certainly deserve garden space for their seed crops, they are not the same thing as pulses. Pulses may seem like just another bunch of seeds, but there are fundamental differences that make them stand alone:

• Pulses are legumes; cereal grains are members of the grass family
• Pulses occur in groups of one to twelve; cereal grain heads produce many seeds
• Pulses contain mostly protein; cereal grains contain mostly carbohydrates

The only true pulses are the seeds from dry beans, dry peas, chickpeas, and lentils. These plants provide one of the best bangs for your gardening buck, providing excellent nutrition and soil health improvement.

Escarole is a ‘bitter green’ member of the chicory family that looks like a lettuce, but packs a powerful nutritional punch. And no Italian wedding soup would be right without it.

Escarole has been eaten and cultivated since Egyptian times. Escarole is an excellent addition to soups and salads, providing both flavor and texture. It can also be baked into casseroles, sautéed, added to pasta, or used to wrap meat or fish. [Lightly sautéing or braising escarole is the best way to bring out its sweetness.] In fact, it is easier to find recipes for escarole than growing tips. But grow it we shall!

The escarole plant

Cousin to radicchio, escarole is a subspecies of endive [on-deev]. The endive species is divided between curly endive or frisée (var crispum), with narrow, toothed leaves, and escarole, or broadleaf endive (var latifolia). Being a type of chicory, escarole has darker outer leaves and pale green to white inner leaves. The degree of greenness to a leaf is an indicator of its bitterness. The chemicals that create the bitterness are said to aid digestion. This group of plants also produces a milky white latex than can cause skin irritation for some.

Escarole, and other chicories, are biennial plants grown as annuals. If you allow them to go through their full lifecycle, as I do, the flowers will attract pollinators​ and you will find escarole turning up everywhere that it can grow!

How to grow escarole

In hot regions, escarole seeds are generally planted in early fall through early spring, successively. This helps avoid bolting, or going to seed, before plants reach full size, and ensures a ready supply of fresh escarole for the kitchen. While they are less likely to bolt than lettuce or spinach, escarole leaves do not taste very good once this process begins.

Escarole is grown much like lettuce, in that it prefers full sun, consistent moisture, temperatures between 50 and 75°F, and a soil pH of 6.0 to 6.8, ideally. Like lettuce, if the soil dries out too much, growth will slow and the leaves will become too bitter to enjoy. Prepare the seed bed by top dressing with aged compost.

Seeds are planted 1/4-inch deep and thinned to 6 to 12 inches apart. Plants growing too close together are more likely to bolt. Side dressing with more aged compost will provide valuable nutrients, retain moisture, and slow weed growth. Escarole also makes a lovely container plant, indoors or out. Escarole matures in 85 to 98 days, depending on conditions.

Escarole pests and diseases

Aphids, flea beetles, beet leafminers, cabbageworms, cabbage loopers, leafhoppers, slugs and snails, and cutworms may feed on your escarole plants, but they rarely cause serious damage. You can use brassica collars to protect young escarole from cutworm damage, and row covers to block many of the other pests. Diseases of escarole include damping off disease, downy mildews, Alternaria leaf spot, Rhizoctonia blight, white mold, leaf rot, and bottom rot.

Harvesting escarole

You can remove outer leaves any time you like, or cut the entire plant off at ground level. Leaving the root system in place feeds the soil microorganisms that help our plants thrive.

Escarole does not freeze well, but many of the recipes that use escarole do, so cook it up and freeze it for later use.