Move over halogen bulbs, the new bulbs on the block are revolutionizing the world of outdoor lighting. LEDs, the light emitting diodes that illuminate our car break lights, alarm clocks, and our household electrical appliance, are exploding into our gardens.
LEDs are so energy efficient that the State of California promotes them for indoor and outdoor lighting. The State’s goal of lower energy use is intended to “reduce air pollution from the burning of fossil fuels in power plants while producing the same quality of light as traditional incandescent bulbs.”
Traditional outdoor lighting is low voltage. A cable connects a string of light fixtures to a transformer that converts household current to 12-volt direct current. LED systems use a driver rather than a transformer to regulate the electricity.
Outdoor LED systems like the ones on this page from Kichler, offer both opportunities and challenges. Experts agrees that silica based LEDs are shatter resistant, a definite plus for outdoors.
Cool temperatures are another plus. Incandescent bulbs generate light by heating a metal filament until it glows. Incandescent halogens can reach 500° F, according to electrical contractor and lighting design instructor Paul Bussell of Ladybug Lectric in Encinitas, California. Extreme temperatures singe leaves, branches, and fingertips. LEDs generate almost no heat, making them safe both in the landscape and to the touch.
While burnt-out bulbs are a common complaint for traditional outdoor lights, LED lifespans are estimated at about 10 years, though, Bussell points out, they’ve not been used in outdoor lighting that long. Only time will tell.
Bussell says that LED light quality is almost up to his standards. “Its hard to put one into an uplight and expect to dim it,” he says, “ and in a sequence of lights, they may not all be the same color. Some might be more blue or more yellow.”
Joe Bell, general manager Lightbulbs Unlimited in San Diego agrees that color is “people’s number one concern. We can get warm whites that look like (the color of) an incandescent bulb….you wouldn’t notice the difference.”
While Bell recommends a driver for new LED systems, he says that for retrofitted systems and those with both halogen and LED fixtures, simply use the existing transformer. Lightbulbs Unlimited also carries LED bulbs that fit into traditional halogen lighting fixtures, “You can retrofit what you have already… Still, you have to match the draw to the transformer.” And if you want to dim an LED, Bell says, use a dimmable driver.
Cost, of course, is a factor. At Lightbulbs Unlimited, a normal halogen uplight may cost $9, while an LED uplight might cost $25 to $45.
Despite the upfront cost, says Bussell “If you factor in usage, longevity and replacement, LED systems are a fifth the cost of halogen systems.”
“Its a huge difference,” Bussell continues, “That one factor alone is the quickest and most efficient way to cut energy use.”
The State of California maintains on-line database of products that meet state-mandated criteria for energy efficiency including LED bulbs. When you visit the database, select the category “Lighting Products,” and the type “High Efficacy LEDs.”
Many people are amazed to learn that there are bulbs native to California. “Bulbs” conjures images of gladioluses, tulips, daffodils, hyacinths, even snowdrops — all of which are native to other parts of the world. But, bulbs native to California? Really?
Nearly all the bulbs offered in nurseries are bold, fancy versions hybridized from far more modest bulbs found in nature. Our native bulbs are on that “nature” scale. While they are not “in your face” the way a fancy glad might be, that doesn’t mean they are any less beautiful. In fact, in many respects, they are even more remarkable looking.
Yellow Mariposa lily (Calochortus luteus), for example, is native to coastal, valley and foothill areas from the Mexican border, almost to Oregon. All mariposas (there are many kinds) are true lilies. Yellow Mariposa lily’s narrow, grasslike leaves stand only 4 to 8 inches tall. From late spring into summer, foot-tall stalks are topped with cup-shaped flowers of bright yellow (hence the name, “luteus”) with burgundy markings. ‘Golden Orb’ is one of the varieties most widely available to gardeners.
The cup-shaped flowers of Calochortus venustus, butterfly Mariposa lily, look very similar to yellow mariposa. Their flowers, though, can range from white to pink, yellow to purple, even reddish brown, often with reddish markings in the center. These are petite bulbs, only a foot or two tall, native to mountains and foothills from the Sierras to the San Gabriels, so they are quite cold hardy. Springtime is bloom time. Plant in full or part sun.
Early onion, Allium praecox, is an onion, but probably not an onion you’d choose to eat. It is one you might choose to grow in your garden, especially since it is one of the earliest blooming native bulbs. Flower stalks emerge from foot-tall clumps of slender, grasslike leaves starting in late winter. Through early spring, stalks are topped in clusters of tiny white to pink to purplish flowers. These bulbs do very well in dry shade.
Tube-shaped springtime flowers of Dichelostemma ida-maia, firecracker flower, are an odd combination of crimson red and chartreuse. Foot-tall flower stalks are topped with a handful of dangling blooms, best seen close up. Since these are higher-elevation bulbs from the edges of forests in north coastal California, they perform best planted in shade or part sun.
Dichelostemma capitatum, known as blue dicks, is similar to firecracker flower, but its flower clusters are upright and purply blue/lavender on taller flower stalks.
Soap bulb, Chlorogalum parviflorum is native to the dry, coastal sage scrub widely found throughout coastal San Diego County. Soap bulb’s slender green leaves grow only about 8 inches tall. In late spring and into summer, tiny, white flowers line stalks 1 to 3 feet tall. Each of the star-shaped blooms has six prominent yellow pollen sacks around a swollen, green center. The bulb part of this plant contains a chemical called saponin. If you wet your hands and rub a bulb between them, you’ll get a handful of soapy foam, hence their use by American Indians. Don’t drink the foam, though, as saponin is toxic. Plant in full sun, where bulbs can go dry in summer.
All of these bulbs live through hot, dry summers with no irrigation. As summer approaches, their foliage withers to the ground. The bulbs are dormant, then, until fall rains, when new foliage appears. They do best under conditions that emulate nature, so plant them in unirrigated areas. They are longest lived in well-draining soils.
Thinking of replacing your lawn but not sure how to kill the grass? Just as we use the sun’s rays to power our houses, heat water and run our cars, we can use the sun to kill lawns as well.
The process, called solarization, uses the heat of the sun’s rays to literally cook plants, weed seeds, nematodes, and pathogens (the “bad guys” that cause plant diseases) in the uppermost layers of soil.
Summer is the best time of year to solarize. The air is warm, but more importantly, the sun has its greatest heating potential. Solarize for six weeks or so and your lawn will be gone with a minimum investment of time, energy, money, and best of all – no herbicides!
Solarization comes to us from the clever folks in Israel where resources are limited but demand is great.
Steps to solarization
1. Cut your lawn very, very short. Make the surface as smooth and even as possible.
2. Irrigate to saturate the soil one to two feet deep
3. Cover the lawn with 2 to 4 ml sheets of clear plastic sheet (available in the paint section of the hardware store. This is the most environmentally ‘unfriendly’ part). Spread the plastic so it is in contact with the soil surface, leaving as little air space as possible
4. Extend the plastic six to eight inches beyond the edges of the grass. The edges of don’t heat as well as the center so extending the plastic assures even heating throughout.
5. If the lawn is large for several sheets of plastic, overlap the seams
6. Anchor the edges of the plastic with rocks, bricks, pieces of wood or mounds of soil.
7. Turn the irrigation off (imagine what would happen if the water went on with plastic covering sprinkler heads!)
8. Wait six to eight weeks.
9. Remove the plastic carefully. If the plastic doesn’t have UV inhibitor (nice but not necessary) it will likely fall apart by the time the lawn dies.
To make the process even more effective, spread a second layer of plastic over the first. Use two-by-fours or bricks to create a few-inch air gap between them. Research shows that the second plastic layer can raise soil temperature another two to ten degrees.
Since the plastic is clear, you can watch the lawn turn from green to yellow, then to straw brown. Once that happens, let the plastic sit another week or two, just to be sure.
Once the lawn is dead, you have a few options. Clear away dead grass where you plan to put walkways or otherwise need an even surface. Where the lawn is to become planting bed, just treat the dead stuff as compost. Leave it in place and plant into, or mound soil atop it. Eventually, it will disintegrate either way.
Since solarization works best in the upper foot or so of soil, don’t rototill or spade after you are done (actually, its best not to rototill ever). Rototilling, or turning the soil deeply, brings seeds and pathogens to the surface where they will again proliferate.
Solarization Q and A
Why irrigate first?
Wet soil heats more quickly than dry soil.
Why clear plastic?
I’m often asked if black plastic works as well as clear. The answer is a definite “NO!” It’s a matter of physics, but rather than give you a complex explanation, here’s an example from our everyday experiences to clarify the concept.
Imagine a hot summer day. Park your car in a sunny parking lot. Roll the windows up, close the doors and leave for several hours. When you return, open the door. What’s your first thought? “Boy its hot in there!” We all know from experience, that the air inside a closed up car gets far hotter than the outside air.
Now, have your car windows tinted. Repeat the process and compare the air inside the car to the air outside.
What happens? Even though the outside surface of the car gets just as hot, the air inside stays cooler when the windows are tinted (like black plastic) than when windows are clear (similar to clear plastic).
This is the “Greenhouse Effect.” Clear glass and clear plastic trap the heating power of the sun’s rays. That’s why soil beneath clear plastic heats up more than soil beneath black plastic. Adding an air gap and a second layer of plastic heats the soil even more.
Can I solarize other areas of my garden too?
Certainly! Raised beds, perennial beds, weed infested fields, even slopes can be solarized to kill weeds, pests and pathogens. Just make the surface flat enough for the plastic to lie tight against the soil. Keep in mind though, that solarization will kill all plants under the plastic so if there are some you want to keep, dig them out first.
According to “,” has a long tradition of being used to heal wounds. Yarrow’s botanical name, Achillea, is after Achilles, who was said to have used yarrow to treat his soldiers’ bleeding wounds. In ancient times, yarrow was called Herba Militaris, the military herb, most likely for that reason.
Today, we appreciate yarrow for other reasons. Our native yarrow, Achillea millefolium, along with European and Asian native yarrows, are mostly low-profile, fast-spreadingthat thrive in full to part sun.
Yarrows take little water once established but grow more lush and “flowerful” with a bit more. They aren’t picky about soil; they even tolerate clay. These versatile little perennials make nectar that attracts butterflies and pollen that attracts beneficial bees.
Perennial beds and grassy meadows are both brightened by yarrow’s broad, flat clusters of tiny flowers in white, yellow, pink, pale lavender or red. Native yarrow grows densely enough to serve as a lawn replacement in areas that get light foot traffic.
Yarrows require little care: plant, mulch, water occasionally once established. Remove spent flowers to prolong yarrow’s bloom. If you have a meadow or a lawn of yarrow, you might use a push mower orto cut back flowers and foliage once plants finish flowering.
You’ll find many yarrows in the nursery. Here are a few to get you started:
•Native Achillea millefolium has ferny green foliage. In spring and summer, native yarrow sports large flower clusters atop 2-foot-tall stalks. ‘Calistoga’ flowers white, ‘Island Pink’ flowers pink, ‘Cerise Queen’ flowers deep rose, ‘Lavender Beauty’ has soft purple flowers, ‘Paprika’ has deep red flowers with tiny yellow centers.
•‘Moonshine’ is a hybrid of European and Asian native yarrows. ‘Moonshine’ is a larger plant with wider, ghostly gray leaves. Flower clusters are broader than the natives’ and bright, buttery yellow. Flowering is in spring and early summer.
•Achillea tomentosa, woolly yarrow, is a more petite yarrow that grows as a mat of tight clumps only a few inches tall. Its leaves are shorter than other yarrows, cylindrical and covered in fine hairs that make the leaves look silvery green (the word “tomentosa” means woolly). This yarrow’s leaves look so fuzzy that your impulse will be to reach out and pet them. Bright yellow flowers make small clusters, just a few inches above the leaves.
Eggplants come in solids and stripes, and all need full sun
Originally published in the U-T, May 6, 2011 at 4:37 p.m
Baba ghanouj, parmesan, roasted, curried or stir-fried with Thai basil … I can’t think of a way I don’t like to eat eggplant. Its soft, creamy texture and its chameleonlike ability to take on whatever seasoning or style I crave make it incredibly versatile and delicious.
I love growing eggplant almost as much as I like eating eggplant.
Huge, voluptuous purple Italian eggplants are a mainstay in my summer vegetable garden. I also grow ping-pong-ball-sized black/purple Indian eggplants, and long and elegantly curved Japanese eggplants. Some years back, I added the creamy-fleshed white- and-purple-striped white eggplant, courtesy of Organic Gardening magazine, for whom I test seeds each summer.
Eggplants grow on 2-to-3-foot-tall annual plants that do best when daytime temperatures are at least in the 70s, and nights are 55 degrees or warmer. Along the coast, that happens around now. Some gardeners start eggplant seeds indoors as early as March to transplant outside now. You can start seeds now, too, to transplant in six to eight weeks. Or purchase ready-to-transplant seedlings starting now to plant directly into the garden.
Eggplants require full sun. They like soil amended with both compost and worm-castings. Space plants about 2 feet apart. Mulch around the plants with aged straw.
Water regularly, using drip irrigation or a hand-held hose (and a lot of patience). Do not water with overhead spray. Fertilize with organic vegetable fertilizer through the growing season. Follow directions on the package.
Lovely lavender flowers develop as the weather warms into summer. Notice that eggplant flowers look like a larger version of yellow tomato flowers. In fact, eggplant and tomato, along with pepper, tomatillo and potato, are all in a plant family called Solanaceae. Their close relationship also makes them susceptible to the same pests, some of which hinder production. For that reason, it is best to have two garden beds. Grow tomatoes, eggplants, peppers and tomatillo together in one bed and alternate beds each year.
Potatoes take up considerable space, so if you grow them, I suggest switching them between their own pair of garden beds.
Ripe eggplants hanging on a plant are so beautiful that I often have trouble bringing myself to pick them. That said, eggplants are ready to harvest when fruits (since eggplants form from flowers and have seeds, they are technically fruits) reach mature size. Read the seed packet or plant label to see what size to expect. Mature fruits will be glossy and firm but not hard. If you aren’t sure, pick one and slice it open. If it is still greenish inside, it isn’t ripe. Each variety ripens at a slightly different time.
My husband harvested our first fingerling potatoes this evening. Its hard to get any sense of their scale from the photo, but the largest ones were not quite three inches long.
He sauteed them in garlic and olive oil, and served them with an asparagus omelette made with fresh eggs laid by my friend Bonnie Manion‘s “girls.”
What more could I ask for a Sunday evening supper!
This amazing combination caught my eye this morning as I arrived home from running errands….
Chartreuse blooming Euphorbia wulfenii, deep purple bearded iris, and Arctotis ‘Big Magenta’ make an amazing display. They were originally planted in different locations but somehow, magically, they’ve drifted together. Another lovely example of garden serendipity…
Wow! My first book, California Gardener’s Guide vII received a rave review by Fine Gardening Magazine blogger Billy Goodnick in his Cool Green Gardens blog. Read it here….
Finally! A garden that fuses my husbands passion for star gazing with my passion for gardening.
The January 18th Astronomy Picture of the Day featured The Kona Galaxy Garden in Paleaku Peace Gardens Sanctuary in Kona, Hawaii. The Kona Galaxy Garden is a 30 m diameter garden bed planted to depict the Milky Way.
According to the website, ” Plant rows were placed to represent arms of our Galaxy, including the Sun’s Orion Arm, the impressive Sagittarius Arm, and the little discussed Norma Arm. A small bar runs through our Galaxy’s center, while a fountain has been built to represent the central black hole. What a stellar use of space!”
What a terrible pun!
Amazing! I feel a trip to the big island coming on any time now….