- Author: Kathy Ikeda
Earthworms. They're so small and seemingly insignificant that we hardly give them a second thought.
These squirmy denizens of the dirt usually go about their lives unseen—they're revealed to us only when upturned in a shovelful of soil or when stranded on pavement after a drenching rain. (Worms crawl out of the ground during heavy storms because they breathe air through their skin and can drown if the soil is saturated with water.)
Even though they can evoke a squeamish response, earthworms are good for the garden. They burrow and create long tunnels through the soil, which helps aerate and loosen it, creates channels for movement of water and oxygen, and allows plant roots to penetrate more easily. They help mix plant matter into the topsoil where beneficial microorganisms can decompose it. They consume organic matter such as fallen leaves, thereby recycling plant nutrients and increasing soil fertility. Worm castings (a.k.a. poop) are an excellent soil amendment since they're rich in nutrients such as nitrogen, phosphorus, and potassium. Research even suggests that plants have improved disease resistance if planted in soil enriched with worm castings. Worms also provide a valuable source of food for birds, frogs, and other wildlife (not to mention being gobbled up by backyard chickens and fish on hooks).
Most of our native local species of worms have been destroyed or displaced by human activity; the kinds we usually see are descendants of hardier worms intentionally or accidentally introduced to North America by early European and Asian immigrants. There are now about 180 different species of earthworms in the U.S. and Canada, a third of which are non-native (including night crawlers). The typical garden earthworms are NOT the same as redworms or “red wigglers” (Eisenia foetida), the non-native species most commonly recommended for use in home worm composting.
Earthworms are primitive but fascinating creatures. They don't have eyes, but they do have special light-detecting receptors. Light is a bad thing for creatures whose natural habitat is underground, and worms have evolved to move away from light sources, hence their burrowing instinct. They “hear” by detecting vibrations, and they produce mucus or “slime” in reaction to stress (e.g. being yanked from the ground). They also have voracious appetites: some species can eat their weight in organic matter every day.
Worms are hermaphroditic: each worm has both male and female reproductive organs in its elongated, muscular, tube-like body. Typically, two earthworms join side-by-side in opposing directions to mate, and each member of the pair produces an egg capsule from which one to several immature worms eventually emerge. Redworms are among the most prolific breeders.
In part due to its reproductive success, some Native American cultures revere the earthworm totem as a symbol of fertility, productive thought, and acceptance of emotions. In our modern society, the worm can represent either the beneficent (as in the sweet, bespectacled bookworm) or malicious (as in harmful software that lurks in the Internet).
This is a good time to discredit a common misconception about worms. If a worm is cut in half by a shovel or by an over-enthusiastic tug from a curious child, the two parts won't heal and live to create new worms. The head end (with its tiny brain and five hearts) can't survive without the tail end (with its digestive system), and the worm simply dies.
You can use several techniques to encourage greater earthworm populations in your garden: (1) Avoid frequent tilling or cultivation of soil; (2) Minimize the use of synthetic fertilizers and pesticides, all of which disturb naturally occurring soil micro- and macro-organisms; (3) Allow leaf litter to remain on soil year-round, to provide a food source for worms; and (4) “Sheet mulch” bare soil, using layers of cardboard, mulch, and compost to keep soil cool and moist and to provide a source of organic material for worms to eat.
A word of caution: don't dump unused live bait worms in a remote natural area. Many forest and mountain environments are naturally devoid of earthworms, and introducing them to those areas can be harmful. Forests often depend on a dense, protective, year-round layer of leaf litter, and earthworms will rapidly consume that thick organic mat.
For more about earthworms in our ecosystem, go online to ucanr.edu and search for the article Earthworm Ecology in California, or read the book “The Earth Moved: On the Remarkable Achievements of Earthworms” by Amy Stewart.
For advice on gardening related questions, call the UC Master Gardener office at 209-953-6112, or use our website: http://sjmastergardeners.ucanr.edu/CONTACT_US/.
- Author: Kathy Ikeda
Have you ever wandered into a garden store, only to be met by a bewildering array of tools hanging from the racks?
Most retail garden suppliers stock an impressive variety of hand-operated (non-power) pruning tools, but offer scant guidance on how to choose the one you really need.
“Tool talk” might not be the most exciting garden-related topic, but it's important to know how to properly use and care for each type of pruning implement.
Hand pruners
These short-handled tools are generally intended for use on plant stems and small branches ½ inch in diameter or less
Loppers
Two hands are needed to operate these long-handled tools, which are designed to cut branches up to 1 to 1½ inches in diameter. Loppers should be used primarily to cut dead or just-removed branches into smaller pieces; avoid using them for pruning, since they tend to damage branches.
Hand pruners and loppers come with two distinct blade configurations, each with special uses and care needs. A third type of blade arrangement applies only to pruners.
- Bypass: This style has a curved upper blade that glides past a lower curved “hook” or “anvil.” The hook holds a stem or branch while the blade cuts. Bypass-type tools are the best choice for most gardening work since they're designed for use on live plant material. The blade is only beveled on the edge facing away from the anvil; the other side is flat. Never sharpen the flat edge of the blade on bypass-style tools; doing so leaves a gap between blade and anvil and causes branches to get stuck in the tool. When cutting, place the blade side of a bypass tool toward the main stem and away from the part being removed.
- Anvil: This style has a straight-edged upper blade that moves downward to meet the center of a flat-surfaced lower “anvil” or “table.” Anvil-type tools should only be used on dead branches—never on live, healthy ones—since they don't cleanly cut all the way through stems and their blade action tends to crush delicate plant tissues. The blade of anvil-style tools is beveled on both sides, so both edges need to be evenly sharpened if they become dull.
- Scissor: As the name implies, this style of hand pruner operates like a pair of scissors, with two short, straight, sharpened blades. They're designed only for lightweight tasks such as pruning tiny twigs and flower or herb stems.
Hand saws
Not all hand saws are designed for pruning use. Carpenter saws, which have straight blades and a hand-hole in the 
Hand-operated pruning tools are also available in “extension” or pole-mounted forms, and some have a telescoping feature that allows adjustment of the pole's length. Pole saws and extension pruners can greatly increase an operator's reach, but they tend to be unwieldy and less precise. For safety reasons, never operate pole-type tools near overhead power lines.
When using any type of pruning tool, be careful to avoid a twisting action while cutting to prevent tearing bark, creating ragged-edged cuts, or damaging tool blades.
It's also important to care for your pruning tools to keep them in top operating condition. Always keep the blades properly sharpened to avoid damaging plant tissues and to reduce pruning effort. Thoroughly clean, dry, and oil tools after use to prevent rusting and to avoid transmitting plant pathogens.
For photos and more information, see Pruning Equipment for Home Gardeners, Sharpening Blades, and Maintaining Lawn and Garden Tools.
Happy New Year!
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website: http://sjmastergardeners.ucanr.edu/CONTACT_US/
- Author: Nadia Zane
A stroll through your garden of late may have revealed some plants with yellowing foliage. There are several possible causes, but iron chlorosis, a condition in which a plant deficient in iron cannot produce sufficient chlorophyll, is common at this time of year. Chlorophyll is responsible for the green in plants and capturing light for photosynthesis, the process in which plants produce food for themselves.
If you have already dashed off to purchase iron, then keep the receipt, because I have a surprise…you probably don't 
To understand how this could be, it's important to know what's happening in the soil. Iron is one of 17 elements essential for plant growth and metabolism. Iron is typically plentiful in California soils, but certain conditions often make it “unavailable” to plants:
Alkaline soil, meaning soil with a pH of 7.0 or higher, holds on to iron (and many other nutrients), making it inaccessible to plants. Most plants prefer a pH around 6.5.
Soggy and/or cold soil limits microbial activity and the important services they provide in getting nutrients to the plants. Microbes need porous soil and a certain temperature range to thrive, which is why chlorosis is more common in winter. Compacted or heavy soils are especially prone to a lack of porosity in cold, wet weather.
Nutrient imbalances, especially an overabundance of zinc, copper, and manganese, can make iron less available. Causes vary, but can be due to over-application of certain fertilizers.
When determining if you do, in fact, have iron chlorosis, consider factors such as watering, the time of year, and then look at the pattern of yellowing on the leaves. Iron chlorosis presents as green veins with the interspaces being yellow, typically on the newer leaves. Other possible causes include Zinc and Manganese deficiencies or exposure to herbicides containing simazine or diuron. See the UC Integrated Pest Management website for pictures of various patterns of chlorosis:
www.ipm.ucdavis.edu/PMG/C107/m107bpleaftwigdis.html
So what can you do? The key is to focus on improving soil health, which can help lower the pH and increase iron availability. Adding compost to the soil and mulching the surface increases biological activity and improves porosity. If the chlorosis appears only in winter (and isn't severe), then simply wait until the soil dries out, and the problem may correct itself. Be sure not to over-water at other times of the year, not just because it's wasteful, but because it can also induce iron chlorosis.
Selecting plants that tolerate alkaline soil can make things easier. Plants native to arid regions, including California natives and other Mediterranean-climate species, have a better tolerance for alkaline soils than acid-lovers such as Hydrangea, Gardenia, Rhododendrons/Azaleas, Camellias, Hollies, Magnolias, and Blueberries. If you must grow acid-loving plants, be sure to apply plenty of compost and mulch, or try growing them in containers where you can control the soil pH by purchasing acid potting mix.
You may go to a garden center and be told that simply adding sulfur will effectively lower the pH. This is correct if your soil does not contain “free-lime” (calcium carbonate), which cancels out the acidifying effects of sulfur. If you have hard water, then you are more likely to have free-lime in your soil. You can test this by taking a small sample of dry soil and adding household vinegar. If it fizzles, then you have free-lime, and you can return that bag of sulfur along with the iron (I hope you kept receipts for both). Keep in mind that highly alkaline soil (above 7.3 pH) cannot be amended enough to grow acid-long plants without ongoing chlorosis issues.
Applications of iron sulfate or chelates to the soil can correct deficiencies if your soil is sufficiently acidic (6.5 or less) and actually needs iron. Remember that simply dumping extra iron into you soil is not going to fix a deficiency if the soil conditions make it unavailable! Foliar applications are good for a quick-fix, though the effects disappear quickly too, meaning you may need to reapply several times a year.
Be sure to avoid Ironite®, an iron supplement containing toxic levels of arsenic and lead. It has been illegal in Canada since 1997, and is under investigation in California. Aluminum sulfate is another amendment to avoid because of the potential for aluminum toxicity. Gypsum has often been touted as a way to lower pH, but this is not true. It increases porosity (drainage) in clay soils with an imbalance of magnesium and calcium, but if your clay soil is “tight” (i.e. holds on to nutrients; not releasing them to plants) for other reasons, gypsum won't do you much good.
With all these complicated explanations and “don't do this” commands, it's actually all very simple: add organic matter such as compost, only apply as much water as is needed to maintain moderate growth, and use plants that are OK with the soil you have. For more information, see the Colorado Master Gardener Notes on iron chlorosis:
www.ext.colostate.edu/mg/gardennotes/223.html
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website: sjmastergardeners.ucanr.edu.
- Author: Nadia Zane
- At a local nursery this past fall, I was excited to find a robust selection of water-wise plants, a reflection of this rapidly expanding market. Another interesting phenomenon, related to me by a nursery employee, was a little less exciting: “customers come in asking for drought-tolerant plants, but change their minds when they see them.” Such news breaks the hearts of Mediterranean garden geeks like me who wish everyone could appreciate the unique beauty of water-wiseplants.
CA Fuchsia in bloom
It's understandable to question what the hubbub is all about then water-wise plants are compared side-by-side with traditional landscape species. Negative reactions tend to fall into one of two categories: 1) “they look different from my thirsty plants, and are therefore ugly”, or 2)” if I search long enough, I will find species looking exactly like the thirsty ones I have now.” Although experience will always affect how we see the world, let us attempt to remove our Hydrangea-tinted glasses for a less biased viewpoint by exploring what makes water-wise plants look the way they do.
One of the first things we notice is how sparse water-wise plants look when compared to the lush, full growth of thirstier plants. It's all about water conservation, as smaller and fewer leaves mean less surface area for water to escape from and less to keep cool in the hot sun. While these acclimated plants can appear strange or unappealing at first, contemplating the paradox of growing lush plants with giant foliage in a hot, dry climate, renders those traditional plants a little more bizarre than before.
Another trait shared by many water-wise plants is fuzzy foliage, which is due to hairs on the leaf surface that protect against excess UV radiation. Plants with smooth, bluish-green foliage have a thick, waxy cuticle that also protects against UV radiation, along with reducing water loss. The soft, supple, bright green foliage found on plants native to regions with summer rain is rare among drought-tolerant plants. California plants native to riparian areas where rivers and streams provide roots with year-round access to water are an exception.
Plants native to hot, dry regions tend to be bushy and low-growing; even our native oak trees, which can reach enormous sizes, naturally grow with low-hanging branches when left to their own devices. This adaptation reduces moisture loss by shading the ground, and protects leaves from the wind, which desiccates by whisking moisture away (think about how dry your skin gets on windy days). Although we love our graceful Birch trees, their single-trunk, upright habit almost screams, “take my water away!”
Winter dormancy certainly isn't unique to our climate, but the extreme heat of summer means some plants shed leaves in late summer to reduce water loss. This can be in lieu of, or in addition to, a winter dormancy. Summer shabbiness is difficult to stomach, but there are some drought-tolerant plants that naturally bloom in late summer. California fuchsias and Buckwheats (Eriogonum species) are two prime examples, sending up plenty of beautiful, pollinator-feeding flowers at this difficult time of year, but without requiring excess irrigation.
Visiting a nursery and comparing drought-tolerant plants with the eye-popping pony-packs of Snapdragons and Petunias can be a tad disappointing. Keep in mind that low-water plants are at their best when their roots have room to spread, which can't happen in a little one-gallon container. Starting small and, I admit, a little scraggly at times, they have great potential for maturing into graceful specimens, providing benefits to pollinators and other wildlife, while asking for less water, maintenance, and fertilizer in return.
If you still find yourself unconvinced, a field trip to a water-wise demonstration garden featuring water-wise plants could provide a more realistic view of what these plants will look like as they mature. The SJ County Master Gardeners have a demo garden by the Stockton airport at 2102 E. Earhart Avenue. For more water-wise demo garden locations, or if you have a gardening related question, you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website at sjmastergardeners.ucanr.edu.
- Author: Kathy Ikeda
The word “bee” usually brings to mind an image of a honeybee, but let's also remember the invaluable contributions and amazing diversity of our lesser-known native bee species.
In contrast, California has about 1,600 species of native bees! They are highly varied in size, ranging from 1/10 to 3/4 of an inch long. Many are scarcely recognizable as bees; some are fuzzy and grey, others are metallic green or blue, and some are even polka-dotted.
Some native bees are “social” and form colonies that nest in hives or large cavities. Bumblebees are the only social native bees in California, and they produce minimal honey since their hives last only a year. They are generalist feeders, foraging for nectar and pollen from different types of plants. They are also “buzz pollinators,” vibrating their wing muscles to dislodge pollen from flowers (a process essential to tomato and pepper plants).
The “solitary” native bees are much more plentiful than the social bees, and they generally congregate only to mate. They don't make honey and are much less likely to sting than social bees since they have no colonies to defend. Approximately 70% of solitary bees are ground-nesting, and they must tunnel into bare soil (not soil that is mulched or covered with plastic). The remaining 30% are cavity-nesting, which means they build their nests in tubular holes (hollow stems, burrows bored in wood, etc.). The females build the nests and often sleep in them, while the males shelter outside.
Solitary bees often have very evocative names: mason, leaf-cutting, miner, digger, sweat, cuckoo, carpenter, and more. Many are generalist feeders, but others (such as the sunflower and squash bees) are specialist feeders, which means they depend on a single type of plant as a food source.
Preservation of native bees is vital for both agriculture and a healthy ecosystem. Amazingly, research shows that some native bee species pollinate crops up to two times as effectively as non-native honeybees. Just as importantly, native bees evolved alongside our native wildflowers and other endemic plants and are best suited to be their pollinators.
Sadly, bee populations are declining, sometimes precipitously. While colony collapse disorder is causing sudden die-off in honeybee hives, native bee populations are also increasingly at risk due to habitat loss, pesticide use, invasive plants and insects, and introduced diseases. One unfortunate example is the western bumblebee (Bombus occidentalis), a once common and important pollinator that has now nearly disappeared from California and other states.
We can help protect and sustain native bee populations by:
- Planting a variety of native and ornamental plants with varying bloom times.
- Providing nesting habitat by preserving some open soil and building bee houses.
- Maintaining buffers of high-quality habitat and native vegetation near farmland, and planting hedgerows with diverse plant species.
- Reducing or eliminating the use of broad spectrum and systemic insecticides, which can harm all types of bees.
To learn more, read “California Bees & Blooms,” an excellent book written by several University of California bee experts. For bee identification guides, pollinator plant lists, and other resources, visit the Xerces Society website (www.xerces.org/pollinators-california-region/). The UC Berkeley Urban Bee Lab website (www.helpabee.org/) has an excellent overview of our state's native bees, information on bee gardening, and instructions for building bee boxes. To see a wide variety of bees, visit the Häagen-Dazs Honey Bee Haven, a public garden near the U.C. Davis campus.
For gardening related questions, call the UC Master Gardener office at 209-953-6112, or use our website: http://sjmastergardeners.ucanr.edu/CONTACT_US/.
