Editor's Picks for 2020

This Month's Pick + Editor's Pick Archive Index

Each month our editor, Barbara Hill, highlights an outstanding plant, interesting insect, or helpful tool.

January

Heavenly Bamboo (Nandina domestica)

I was hesitant to choose a plant that isn’t native to our area, particularly one that is toxic to birds and animals. But it puts on such a lovely display of color during the holiday season that the pick for January is Nandina domestica. Although its common name is Heavenly Bamboo, it isn’t a member of the bamboo family. Nandina is native to eastern Asia, and has been cultivated as an ornamental in Japanese gardens for centuries. In fact, its species name is a Latinized version of a Japanese name for the plant, nan-ten. In Shanghai berried sprays of nandina are sold in the streets at New Year to decorate house altars and temples. During this season in our area, nandina sports bright red berries, and its leaves range from a bright, clean green to light and deep reds: perfect for festive indoor bouquets. I add a few sprays of the salvia called bee’s bliss for a softer texture and a contrasting sage green. Just be sure to keep the berries out of reach of your pets!

Guest Editor Laura Lukes, Photo by Laura Kling.

February

The Buzz About Biochar

Although it may be a new term to many gardeners, biochar has been used in agriculture for thousands of years. Amazonian tribes and other early civilizations grew crops in soil made rich with compost, mulch, and biochar. The soil created by these ancient gardeners remains remarkably fertile, even today.

Just what is biochar? Simply put, it’s a type of charcoal that’s created by burning organic material slowly, with a restricted supply of oxygen. The fire is doused before the material is reduced to ash, leaving coarse chunks that are riddled with open spaces. When buried, these crevices can help soils retain moisture and nutrients, and offer a safe haven for beneficial microorganisms.

Proponents claim biochar production will also help reduce global warming. When organic matter decomposes, it releases carbon dioxide into the atmosphere, contributing to climate change. There is evidence that biochar stores, or sequesters, a significant amount of that CO2, potentially for thousands of years, making it a carbon-negative product.

While many are hopeful, more study is needed to determine whether biochar will live up to its advocates’ billing as a global panacea. Scientists around the world are working hard to help us fully understand its potential uses and overall impact on soil health, crop productivity, biomass waste reduction, and mitigating drought and climate change.

Should home gardeners jump on the biochar bandwagon? Current evidence suggests that, used with compost, it can help add fertility to depleted soils, as well as improve its texture and moisture-holding capabilities.

For more information:
Biochar for Environmental Management in California (pdf)
Making and using biochar at home (pdf)

Photo: UC Davis Biochar database

March

Lenten rose (Helleborus x hybridus)

Compared with the demure lenten roses of their era, the wanton ways of modern hellebores would likely have had Victorian ladies clutching their pearls. Interbreeding freely with H. orientalis and a host of other hellebore species, the modest flowers of yesteryear are now overshadowed by their lush cousins, which grace late winter and early spring gardens with a dazzling array of colors, shapes, and patterns. No fainting couch required for these robust beauties, either: they’re as vigorous as they are floriferous. Attractive even after shedding their floral finery, their glossy, deeply-lobed, evergreen leaves form mounds 18" to 24" tall and 24" to 30" wide. Provide shade and low to medium water, and remove old flower stalks in autumn.

Photo by Old Itch.

April

Leafhopper assassin bug (Zelus renardii)

Move over, lady beetles—there’s a new beneficial in town. And it might just turn the tables and take a bite out of you.

Zelus renardii, also known as the leafhopper assassin bug, is an unassuming-looking insect. Slender and long-legged, adults reach a modest three-quarters inch in length. Bulging eyes and elongated heads give them a rather comical look, and when they take flight, they bumble and buzz about ineffectually. But don’t be fooled by the innocent veneer: this bug-next-door is a stone-cold killer. Lying in wait, or stealthily stalking its chosen quarry, the aptly-named assassin bug ruthlessly stabs captured prey with its long, needle-like beak. Next, a venom is injected that both paralyzes its victim and dissolves its internal tissues. The resultant goo is then slurped up, using the beak like a straw.

A California native, this predator has been trolling our gardens for a long time, but has just recently received recognition for its role in controlling the reviled glassy-winged sharpshooter.

Although valued as a beneficial, leafhopper assassin bugs, like praying mantids, are generalists. They will help rid your garden of pests like aphids, caterpillars, and cucumber beetles, but will also happily snack upon good guys like bees, lacewings, and—alas!—lady beetles. Gardeners must also be wary: if disturbed, this pint-sized predator may deliver an intensely painful bite.

Learn about:
Assassin bug
Glassy-winged Sharpshooter

Photo provided by: UCANR

May

Organic Herbicides

It’s that time of year when “pesky” doesn’t begin to adequately describe the weeds in our gardens. You can hoe, burn, pluck, and stab all day long and then start over again tomorrow! And while these mechanical and “cultural” practices are part of a recommended integrated pest management approach to controlling weeds, so too is the appropriate use of herbicides—i.e., chemicals.. But of course, using herbicides requires caution: we’re all aware of growing concern around glyphosate-containing products (such as Roundup), now forbidden, for example, at all University of California locations, including Master Gardener Demonstration Gardens. So it is good to know that alternative and organic herbicides are being studied carefully, and the results are starting to come in.

Research to date suggests that not all organic herbicides are equally effective. Their effectiveness depends upon their ingredients, and the rate, frequency, and time of application. Generally speaking, organic herbicides require repeated applications and higher temperatures or sunny days, but they can succeed in controlling those grasses and broadleaf plant pests you curse in your garden. Among the more promising products are ones that contain Pelargonic acid, a “fatty acid soap” which occurs naturally in products as diverse as goat’s milk, apples, and grapes. Research to date shows less promise for clove oil, another ingredient in popular organic herbicides, while acetic acid—vinegar—gets mixed results.

See these resources to delve further into this fascinating topic:

Guest Editor: John Ober

June

Public Enemy #1, or Good Samaritan?

Google “mud dauber wasp,” and nearly half of your hits will be from pest control companies.

It makes sense. Even prior to recent headlines about so-called “murder hornets,” wasps can understandably evoke a sense of dread. But are all wasps alike?

Unlike social wasps such as yellowjackets which aggressively protect their nests, mud daubers are solitary, peaceable sorts who only sting if handled roughly. Better yet, rather than being dangerous, they’re garden beneficials. Because the adults’ only food is flower nectar, not only will they never disrupt a barbecue, they actually help pollinate our plants.

And if spiders make you squeamish, you’ve got even more reason to befriend these beneficials: mud dauber wasps prey exclusively on those leggy arachnids, with black widows being a favorite. Ferrying gobs of mud in their mandibles, females build their nests one cell at a time, packing each with dozens of live spiders that have been paralyzed with a sting. When the cell is thoroughly packed, the wasp mom will deposit a single egg, cap it off, and start on the next one. With up to twenty cells per nest, that’s hundreds of spiders dispatched! When her young hatch, the larva will dig into the waiting feast, pupate when the table is bare, and when mature, start the process all over again.

Visit UCANR’s Green Blog to learn more about mud daubers.

Photographer: Alvesgaspar

July

Celebrate the Fourth of July all summer long with this fiery, floriferous globe amaranth!

Gomphrena globrosa “Fireworks” adds pop and sizzle to any garden, from midsummer ’til Thanksgiving. Large, magenta-pink blooms tipped with bright yellow starbursts are held aloft on long, strong stems, proudly waving above the compact plant. Long-lasting in bouquets or dried for year-round displays, this annual happily self-seeds, keeping the celebration going for years to come. 1–2' tall x 3' wide. Heat and drought tolerant, and unfussy about soil. Sun to part shade; average to low water.

Photographer: Jacopo Werther

August

Have you ever wondered why the longest day of the year isn’t the hottest?

After all, the summer solstice, which marks the day we receive the most direct sunlight, is in June—why is it our weather doesn’t really heat up until late July and early August?

This enigma is due to a phenomenon known as “seasonal lag.” Turns out, it’s not just the sun’s warmth we have to take into account; we must also factor in the earth’s surface and a little thing physicists call “thermal inertia.” According to Merriam Webster, this is “the degree of slowness with which the temperature of a body approaches that of its surroundings.” If that body is very large and very cold, like a frozen land mass or an icy ocean, it will be particularly resistant to changes in temperature. So, the sun can glare all it wants—earth’s land and waters will hoard winter’s chill and take their sweet time warming up, and while that’s happening, our ambient temps will be cooler. In wintertime, we get the other side of the coin: December’s shortest days may be plenty cold, but they’ll still be warmer than frigid January.

In fact, we experience this effect every day: it’s thanks to thermal inertia that, even though summer’s sun is hottest when it’s directly overhead at solar noon, we and our gardens don’t hit full wilt until several hours later.

More about the seasons (plus, pictures!).

Photographer: Ian Paterson

September

Some Good News

Catherine the Great is quoted as saying, “Bad news travels faster than good.”

While it’s true the former seems to be breaking the sound barrier these days, good news is out there—lots and lots of it. From humble to Herculean, the acts of everyday heroes inspire and console. Joining their ranks are researchers and innovators who are working hard around the clock, around the globe, to solve some of the world’s greatest challenges. Although most won’t grab headlines, exciting discoveries are happening every single day. Here’s a sampling of just three:

Nootakone: 1 Malaria: 0 !
Noota-what?

This tangy food additive, discovered and developed by the CDC, now looks to be a game-changer in the prevention of deadly insect-borne diseases. If you’ve ever sipped a Fresca, you’ve put it in your stomach—and thanks to recent FDA approval, we’ll soon be applying it to our skin.

A nontoxic chemical found in grapefruit and cedars, nootakone has been proven to be as effective as DEET and other synthetics at repelling a variety of insect pests, and in higher concentrations, is a safe and effective insecticide.

Photosynthesis 2.0!
The international RIPE project, led by the University of Illinois, has been working to improve photosynthesis by devising ways to help plants manufacture sugars more efficiently. Their goal: “To equip farmers worldwide with higher-yielding crops to ensure everyone has enough food to lead a healthy, productive life.” In a recent study, researchers were successful in boosting their model crop’s productivity by twenty-seven percent—and even conserved water while doing so. That in itself is a huge breakthrough, but they’re not stopping there: RIPE Director Stephen Long believes combining these results with previous discoveries could result in increasing crop yields by as much as fifty to sixty percent.

Bird species saved from blood-sucking maggot!
It may sound like sci-fi horror, but it’s all too real: macabre parasites were quickly driving a tiny Tasmanian bird into extinction. Australian National University’s scientists came to the rescue. By pairing good ecological data and clever problem-solving with a few inexpensive hardware store items, they were able to pull this ping-pong-ball-sized songbird back from the brink. There’s lots to celebrate beyond the survival of the forty-spotted pardalote: the success of this simple, innovative solution serves as an important model for natural resource managers the world over, as they work to help imperiled wildlife.

Photographer: Patrick Kavanagh

October

It's Time to Plant Trees and Shrubs

Shine up those shovels! Autumn is the best time to get new trees and shrubs in the ground. Whether you’re populating a brand-new site, or adding plants to existing beds, choosing wisely now will help ensure years of enjoyment.

Health first
Plants that have been well cared for in the nursery will perform best in your garden. Look for specimens sporting vibrant foliage and robust roots, and pass on anything leggy, weedy, or showing signs of pests or disease. Consider giving the soil a “sniff test,” and move on if you detect a sour odor or whiff of rot.

Think foliage, not flowers
Unless you’re just looking for a quick pop of color, avoid plants bursting with blooms. Although tempting, they’ll struggle to go the distance, since they’ll be expending all their energy on flowering, rather than growing strong roots and leaves.

Check the tag
Ensure long-term success by matching a plant’s growth habit and cultivation requirements to its eventual home. A sun-loving, xeric manzanita would keel over in the shady moistness beloved by Sierra iris, and petite foothill penstemons would be better alongside a narrow path than a rampant California rose.

Avoid invasives
Happily, most nurseries no longer trade in the worst of these ecological and economic disasters, but some of those baddies are still out there. Learn about attractive alternatives to the worst offenders.

Consider natives
According to the California Native Plant Society, “California’s native plants...have co-evolved with animals, fungi and microbes, to form a complex network of relationships. They are the foundation of our native ecosystems.” In other words, these plants are the original garden good guys, providing native bees, butterflies, birds, and other wildlife with a smorgasbord custom-grown to help them thrive. Plus, bonus: native plants are generally easier to care for once they’re established, and require little or no pruning, watering, deadheading, or fertilizing. Whether you start small (say, planting a few milkweeds to help imperiled monarch butterflies), convert entire beds, or land somewhere in between, you’ll be joining a trend toward sustainable, site-suited, fauna-friendly gardens.

Photographer: Mari Moore

November

Create Safe Havens for Native Bees

We’ve heard a lot about planting to attract and support our precious pollinators. Providing ample and diverse sources of nectar and pollen for them is vitally important, but we can do even more: creating safe havens for native bees to hibernate and raise their young will help them, and your garden, thrive!

Check into bee hotels
Only honey bees form hives. Thirty percent of native bees seek out cavities in hollow stems, dead wood, even cracks in stone to lay their eggs, while the remaining seventy percent nest in bare earth.

For cavity nesters, bee hotels, or houses, don’t need to be Instagram-worthy. Whether you roll out the welcome mat with a store-bought extravaganza or just a few lengths of bamboo bundled together, be aware that correct dimensions and materials are key—as is, of course, location, location, location.

Delay deadheading
Just as we leave seed heads to feed birds through winter, we can also delay the removal of the hollow or pithy stems of plants such as hyssop, aster, and goldenrod, which offer great homes for many stem nesters.

Leave logs
Dead trees supply important habitat for myriad creatures, including native bees, but can be unsightly or downright hazardous in the garden. Logs tucked in out-of-sight spots will attract carpenter beetles, whose bored holes become ideal egg chambers.

Mulch matters
A nice, thick layer of wood chips is great for planting beds, but bad for ground nesters. Consider creating bee nurseries in your yard by leaving a few sunny spots unmulched, or use lighter materials such as shredded leaves or compost: still great for your soil, but light enough to admit mama bees. Learn what ground nesting bees need.

Bottom line: Native bees help our gardens propagate—let’s help them do the same! Find out what you can do to increase nesting habitat for native bees.

December

Tools and Books

If you're craving something that'll take your 2021 garden to the next level, but think your head might explode should you hear “All I Want for Christmas” one more time, consider doing your window shopping safely at home. To start you off, here are a few items from my New Year's wish list:

Impulse-purchased bulbs all too often end up as wizened mummies, guiltily tossed on the compost pile. This type of whiz-bang garden auger ought to make all that digging a breeze.

Ratcheting pruners like this are touted for overworked or arthritic hands. If you too have broken your share of “unbreakable” spades, don't give up the search—there may be even sturdier options out there.

It pays to keep your tools sharp, and sometimes professional intervention is the way to go. Folks like those at family-owned Fanno Saw Works, who have been sharpening tools for over 100 years, can help.

There's always a place on the bookshelf for new garden inspiration. I'm leaving a space for this one: Chico's own garden guru, Jennifer Jewell, follows her inspiring book, The Earth in Her Hands, with the hotly-anticipated Under Western Skies: Visionary Gardens from the Rocky Mountains to the Pacific Coast, due out next April.

Shameless plug: Compiled and edited by our stellar Master Gardener Garden Guide team, the second edition of the popular Butte County Garden Guide and Three-Year Journal is now available, with new articles, updated information, and plenty of space for garden jottings. All proceeds go to the Demonstration Garden at Patrick Ranch and other Butte County Master Gardener community outreach projects.