Lambsquarters: Weed harvested as wild food

Lambsquarters (Chenopodium album) is such a common weed that it’s vanished into the visual background, invisible by its ubiquitousness. Humans ate it before the Stone Age, and modern-day foragers seek it out for its taste, abundance and usefulness. But it is an invasive plant that not all  gardeners want in their space, explaining why common names vary from Allgood and Baconweed to Dirtweed.

Spring is the best time for collecting wild lambsquarters, but you can eat it as a backyard crop through the summer. The plant prefers partial sun or shade, and with a little water and almost no care, it will thrive. One purple-tinged variety called giant goosefoot (Chenopodium gigantium) is easily available in seed form as Magentaspreen. In the garden it grows far more easily than spinach (a close relative) and can get 6 feet high. It’s sometimes called tree spinach, with good reason.

This is a fast-growing, cut-and-come-again vegetable that can be harvested within a month of sowing. It's a nitrogen fixer, improving the soil. But more important, you can pick off the tenderest leaves from the top and sides, blanch them briefly in water to remove the oxalic acid and use them just like spinach, kale or collard greens.

The Dry Garden: Ornamental grasses, poetry in motion

There is nothing lovelier than tall ornamental grasses, backlit and waving in a breeze. Even vacant lots can produce stands of car-crash-inducing beauty. So when gardeners hope to capture some of that lyrical action for their own homes, it’s logical to assume that all one need do is stop mowing the lawn. Alas, that would be wrong. Harnessing the tousled romance of ornamental grasses (and plants that look like these grasses) is so hard that even experienced horticulturists factor generous time and space for trial and error into their approaches before they have, in effect, allowed the right plant to do its stuff in the right place.

Among the challenges are discovering these meadow grasses' growing seasons, understanding which ones are invasive, watering them enough but not too much, deducing where they are happiest, out-competing unwanted turf grasses and remnants of lawn and, hardest of all, mastering scale. If you haven’t put a tall grass where a short one would be better, or big one where a small one should have gone, you haven’t been bitten by the meadow bug.

Grasses and their doppelganger cousins -- rushes and sedges -- come in so many shapes, sizes and habits that they can serve as filler, accent or focal point in a garden. These ultimate functions are rarely clear when they are enigmatic little clumps sitting in flats or 1 gallon pots on nursery shelves. Repeating the mnemonic “sedges have edges, rushes are round, grasses are hollow right up from the ground” will help take the edge off as you admit helplessness and look for a knowledgeable store clerk.

Given that knowledgeable staff in garden centers are almost as rare as hens teeth, the best place to go for help is the Theodore Payne Foundation for Wildflowers and Native Plants in Sun Valley, above right. Signage around an impressive and growing selection of grasses alerts shoppers to what might be Lesson No. 1 in landscaping with grasses: These plants divide into two distinct classes of cool and warm season growers. So if you want growth and color in fall, winter and early spring, go for cool season. If you want it in summer, choose warm season. Payne also has helpfully divided the grasses and sedges into separate areas for plants favoring wetter or drier conditions.

Gardening hangovers, Part 5: Scotch and Spanish broom

One of those gorgeous winter days when the interplay of light, mist and silvery white ceonothus makes the Santa Monica Mountains sparkle, National Park Service ecologist Christy Brigham steps onto the Backbone Trail.

She points out the skeletons of shrubs she’s been trying to kill: fragrant, yellow-flowered Spanish broom (Spartium junceum). The plant is mild-mannered in its homeland. But once abroad, away from the diseases and insects that used to keep it in check, this broom can become plant-zilla, bulking up quickly and out-competing indigenous plants.

It spits out seeds — they explode out of drying pods — that can fly or roll quite a distance. Hikers also tramp them into the wilderness. “Any place you get a disturbance — a gopher mound, a fire — they will grow into these big bushes,” says Brigham.

The shrub is also colonizing parts of the San Bernardino Mountains that burned in 2003.

Spanish and Scotch brooms were planted, years ago, along many of California’s mountain roads to stabilize soils. They’re also sold in nurseries.

California nurseries aren’t allowed to stock some of the worst weeds, especially those that threaten agriculture. But, according to Doug Johnson of the nonprofit California Invasive Plant Council, “State law actually prevents plants currently in the nursery trade from being banned.”

The U.S. may soon require tighter screening of new horticultural imports. However, Johnson says, it’s unlikely to place new restrictions on plants already in home gardens, “so it’s important that we develop voluntary measures.”

One such effort is California Horticultural Invasives Prevention, a consortium that urges the nurseries and gardeners to avoid invasive plants.

Azusa-based Monrovia Growers, a member of Cal-HIP, has replaced many runaway plants with less aggressive alternatives. The company’s computer system won’t allow salespeople to ship invasive plants to regions where they threaten wildlands, according to Nicholas Staddon, director of new plants. Staddon keeps a wary eye on new imports: “I’ve learned to look for certain traits in plants that could mean they’ll become invasive.”

But Monrovia offers Spanish broom and Mexican fan palm on its website, which doesn’t identify them as potentially weedy. And other companies continue to sell about 30 of the state’s worst weeds.

“The issue has been bewildering for the industry,” says Craig Regelbrugge, a vice president at the American Nursery and Landscape Assn., because some invasive plants vary regionally and “the science is fast evolving.”

Scientists know that some species of broom, pampas grass, and ivy are invasive, but which of their cultivars threaten wildlands is unclear. Research suggests pampas grass cultivars that seem sterile in nurseries are nevertheless contributing pollen to feral populations, helping them spread. Some weeds are also hybridizing in the wild, making identification difficult.

Gray areas and divergent perspectives cloud consensus efforts. For instance, Staddon argues some of the especially useful runaways should be allowed in “highly populated areas where they will never have the opportunity to become invasive.” 

“It’s ridiculous to think nurseries would ask every customer how urban they are and base their sales on our response,” says invasive plant educator Drew Ready, “It just won’t happen.”

He estimates some 5 million California homes are within a few miles of a wildland, creek or park.

So land managers such as Brigham could be weeding indefinitely, and scrambling to pay for it. “If we can prevent people from planting these weeds, that’s money the Park Service can spend on other things — interpretative and education programs — things that people are excited about.”

To find alternatives to invasive garden plants, check these websites: plantright.org, cal-ipc.org, and weedwatch.org.

-- Ilsa Setziol

Photo: Scotch broom. Credit: Los Angeles Times

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Gardening hangovers, Part 4: acacia

On a recent morning, a northern harrier — a large raptor — spirals up into the blue over Ballona Wetlands, until it looks as if it’s gliding over the snowcapped San Gabriel Mountains in the distance.

For the harrier and some other animals, Ballona is one of the few — if not the only -- habitable spots remaining in coastal L.A. County.  Many of these species, including the endangered Belding’s savannah sparrow and the county’s last burrowing owl, need low-growing habitat such as pickleweed or native dune flowers (silvery leafed lupine, beach evening primrose).

Volunteers have restored some of the native vegetation at this 600-acre degraded wetland near Playa del Rey, but Ballona still hosts a who’s-who of aggressive exotic plants known as invasives: ice plant, pampas grass, Brazilian pepper tree, myoporum, eucalyptus and various acacias. These plants hamper restoration efforts on a parcel the state spent millions to acquire.

Conservation biologist Dan Cooper points out one of the acacias. It “probably has some nutritional value, but the main birds that feed upon it are nonnative pest species like starlings.”  The seeds survive digestion and sprout up in thick clumps. “It’s changed the habitat from being open, which a burrowing owl would like, to being basically a thick hedgerow which it can’t use.”

The nonprofit California Invasive Plant Council advises gardeners to pass on four weedy acacias — cyclops, longifolia, decurrens, and baileyana.

At least eight more of the 1,200 species of acacia have naturalized in California wildlands. They’re not widespread now, but many invasive plants lie low for years before running amok. And horticulturists continue to offer new acacia selections.

Often called wattles, acacias are common in parts of Australia, with a climate similar to California’s, so many are likely to thrive here. "The very plants we promote for saving water in gardens, which are often the Mediterranean-climate plants, in some cases have the greatest potential for being invasive,” says Jim Folsom, director of botanical gardens at the Huntington. He notes that thirsty tropical plants are less likely to invade Southern California wildlands.

The acacias and other exotic plants at Ballona have advocates who point out that some native animals use them. For Cooper, that’s analogous to feeding kids candy because they like it. “Just because a species uses something doesn’t mean it’s good for the species or something we want around,” he says. 

California flora are rich in evergreen shrubs, so water-conscious gardeners can choose from several alternatives, including coffeeberry, lemonade berry, and holly-leaf cherry. An exotic shrub that stays put is pineapple guava, which produces showy, edible flowers and fruits with a minty-pineapple flavor.

-- Ilsa Setziol

Coming Friday: Scotch and Spanish broom

Photo: Acacia longifolia

Credit: Genaro Molina / Los Angeles Times

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Gardening hangovers, Part 3: fountain grass

Grasses are among California’s most prolific weeds. Exotic bromes and other annual grasses now carpet millions of acres, displacing of native wildflowers, bunch grasses and shrubs.

Most arrived with 19th century settlers and livestock (as contaminants in feed or lodged in animals’ coats, for example). But in recent years, ornamental grasses have joined the fray.

“Grasses are useful in a landscape,” says Jim Folsom, director of botanical gardens at the Huntington, “but by nature they are invasive; being a grass generally means being able to cover a lot territory fast.”

A nasty example festers at Arcadia Wilderness Park. Three acres of a steep, dry slope are bristling with a billowy plant with fuzzy seed heads, called fountain grass (Pennisetum setaceum). This runaway garden plant is also slurping up water in a nearby stream bed. Drew Ready of the nonprofit Los Angeles and San Gabriel Rivers Watershed Council says it’s converted “a biologically diverse stand of chaparral” into “a biological wasteland.”

The grass’ bad seed gets around easily — roving perhaps miles in strong wind. It has most likely already plopped into the adjacent Angeles National Forest, and needs only a disturbance -- fire or mudslide — to spread rapidly.

Like other alien grasses, fountain grass makes wildlands more fire-prone. “It provides a layer of really fine fuel that ignites very easily,” Ready explains. Coupled with an increase in human-sparked fires, exotic grasses threaten to extirpate plant communities on Southern California’s hillsides, including rare coastal sage scrub habitats. “Native species can’t endure these frequent fires and die off,” says Ileene Anderson, biologist with the Center for Biological Diversity.

In an attempt to keep fountain grass from escaping gardens, horticulturists have selected cultivars that aren’t supposed to reproduce, including purple-colored ‘Rubrum.’ But Ready doesn’t think they’re a safe bet: “Most nurserymen will tell you they’re not always sterile.” 

Ready advises gardeners to avoid all fountain grasses. “There are so many safe and beautiful alternatives,” he says, listing native deer grass, blue oat grass and "Canyon Prince" wild rye as examples.

He’s also concerned about the recent popularity of Mexican feathergrass; “because it spreads so readily by seed, it’s at best a garden nuisance; at worst it will become as much of a scourge as fountain grass.”

The Watershed Council promotes alternatives to the region’s most invasive plants on its Weed Watch website.

-- Ilsa Setziol

Coming Thursday: acacia

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Photo credit: Ricardo DeAratanha / Los Angeles Times

Gardening hangovers, Part 2: Mexican fan palms

When many of us think of Los Angeles, there’s a palm in the picture. That palm is likely Washingtonia robusta, the Mexican fan palm.

Mexican fans are the remarkably tall (up to 100 feet), skinny palms with fan-shaped fronds that have towered over much of the city’s built environment for more than a century. More conspicuous than stars in L.A.’s washed-out night sky, some palm constellations have even been dubbed historic-cultural monuments.

Although other palms have sneaked into the scene, Nicholas Staddon, director of new plants for Monrovia Growers, says Mexican fans are still popular and “very valuable — it’s fast-growing and has a wonderful tropical look.” No primadonna, aptly named robusta thrives in a couple square feet of dirt amid a sea of concrete, even roots in sidewalk cracks.

But the region’s palmy past is seeding trouble. “Most of the dates fall nearby,” says licensed herbicide applicator Bill Neill, “but some will eventually go down the storm drains into the river channels.”

To restore ecosystems, Neill kills aggressive weeds called invasives. He’s whacked and sprayed vast thickets of bamboo-like arundo along the Rio Hondo and San Gabriel River. When grant money is available, he also drills into the trunks of Mexican fan palms, then fills the holes with weed killer.

Left to their own devices, palm groves could shade and crowd out crucial habitat, including an unpaved, two-mile stretch of the Rio Hondo that borders Rosemead. There the river flows freely across the earth. Native willows, mule fat, elderberry and black walnut support rare birds, including the endangered least Bell’s vireo and the yellow-breasted chat.

Mexican fans also reduce the flood-control capacity of the L.A. River (and others). Any vegetation will slow water flow, but the U.S. Army Corps of Engineers rips out invasives before it touches native plants. “Willows don’t burn easily,” says Corps ecologist Carvel Bass, “but fan palms and arundo do, and they don’t contribute to the habitat in any positive way.”

Mexican fans and other weeds often get a leg up when people tinker with natural systems. Many of Southern California’s formerly intermittent streams now pulse with water year-round, creating an oasis for the palms.

On its Weed Watch website, the nonprofit Los Angeles and San Gabriel Rivers Watershed Council recommends alternatives to invasive plants, including palms such as Blue hesper (Brahea armata) and Guadalupe Island fan (Brahea edulis). Gardeners could also turn to Washingtonia filifera, the Mexican fan’s stockier, slower-growing cousin, indigenous to Southern California deserts.

Although the long-lived Mexican fans are likely to be a fixture of L.A. for some time, they and their fronded relatives may become less common. These days, city foresters favor broad-canopied trees, which offer more shade to city streets.

-- Ilsa Setziol

Coming Wednesday: Fountain grass

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Photo credit: Brian Vander Brug / Los Angeles Times

Gardening hangovers, Part 1: periwinkle

Ecologist Christy Brigham stands amid willows hemming Medea Creek in the Santa Monica Mountains. The trees’ amber leaves glow in the morning light. She frowns at an ivy-like plant with violet-blue flowers. It’s blanketing a large swath of the creek. “Periwinkle is a common landscape ground cover,” she says. “It’s attractive to some people. I think it’s a green menace.”

Periwinkle (Vinca major) hails from the Mediterranean. Let loose in parts of Southern California, it smothers virtually all of the wildlife-supporting native plants in its path. California is home to many indigenous plants found nowhere else on Earth. Many are at risk of extinction. The main culprit is urbanization, but weedy exotic plants — even some that residents buy for their gardens — often share the blame. Able to rough it in the wild, runaway plants can throw entire ecosystems out of balance.

Each day this week, I'll highlight one of these rogue beauties. Today: periwinkle, one of about 300 nonnative plants that have taken root in state and federal parks in the Santa Monica Mountains. Most are fairly benign, but the National Park Service spends as much as $400,000 a year to keep 19 especially destructive weeds at bay. Statewide, the cost of controlling the most invasive weeds on public lands is estimated conservatively at more than $82 million a year.

A tiny piece of water-slurping periwinkle can launch an infestation that will take the National Park Service 10 years to quell. “I’m sure what’s happened is that someone upstream has this on a bank,” Bringham says. “This species has vegetative propagation; as stem and root fragments break off, they wash downstream and become established.”

Medea Creek is a tributary of Malibu Creek, a rare perennial stream that’s vital for wildlife. The periwinkle alters the creek’s flow and covers gravel beds.

“It’s stabilizing soils that should not be stable,” Brigham says. "There should be a lot of open spaces — open sediments that are used by amphibians and reptiles.” If the periwinkle washes downstream, it could destroy breeding pools for the endangered southern steelhead trout.

To Brigham’s dismay, some California nurseries still sell this periwinkle, Spanish broom, fountain grass and other aggressive exotic plants known as invasives.

The nonprofit California Invasive Plant Council hopes California gardeners will protect wildlands by choosing alternatives it promotes on its website. Periwinkle substitutes include ivory star jasmine, beach strawberry (Fragaria californica or Fragaria chiloensis) and wall germander. Dwarf periwinkle (Vinca minor) is less invasive, but it's still not recommended.

The invasive plant council advises gardeners to pass on two other ground covers: ice plant (Carpobrotus edulis) and ivy. The former has taken over miles of California’s coastal dunes, displacing rare plants; some ivy species not only shroud the ground, they climb trees and kill them.

Invasive plants don’t just threaten wild species, Brigham says. They rob people of a wilderness experience.

“You should be able to go to your park and see the native plants and how they interact with animals," she says. "When places become degraded and dominated by a plant from another landscape, you don’t have that experience.”

-- Ilsa Setziol

Coming Tuesday: The trouble with Mexican fan palms.

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Photo credit: Los Angeles Times