We have had a lot of frost this year! According to the weather records from the station west of UC Davis, there have been 18 mornings cold enough for frost since Nov. 1. This is a pretty typical La Niña pattern. Low rainfall = low dew points, less fog, and more frost on a clear, still night.
Lowest readings have been the mornings of Dec. 24 and 25 when that weather station recorded 24 degrees. Ordinarily temperatures that low could be expected to do pretty serious harm to citrus and other subtropicals. But damage so far has been minimal.
Microclimates are making a big difference. The areas up against your house on an east-facing or south-facing walls are several degrees warmer due to heat stored during the day, and are warming up quickly when the sun comes out. Cold damage on a plant is a combination of absolute temperature and duration. These frosts have been cold, but short duration.
Dry soil can lead to further damage from cold as plants desiccate. We are way behind on rainfall, with less than half of normal to date. Water newly planted plants, those in containers, and larger citrus and subtropicals. You can simply run your sprinklers through one cycle, or give each plant a quick soaking with a hose.
If your plant is showing damage, it's best to just leave it alone for now. Cutting back frosted leaves and stems opens the plant up to further damage. Those wilted, curled leaves, in some cases, actually provide a small measure of frost protection for parts of the plant further down. I prefer to wait until spring and let the plant begin to grow before pruning. Let the plant tell you how far to cut it back; just cut to the new growth when it occurs.
You've probably already figured out that your summer annuals won't be coming back. Impatiens, coleus, marigolds, and their ilk are dead. Don't rush to rip out begonias, as they often do resprout in spring from the base. Winter annuals are impervious to the cold. Pansies and violas, snapdragons, stock, ornamental cabbage and kale, and paludosum daisy may bend over with frost, but will perk right back up when the sun is upon them. Winter-flowering perennials such as cyclamen are also unaffected. Likewise in your vegetable garden: the salad greens, broccoli, cabbages, onions, and others are all perfectly hardy.
[Science quiz! Why do some plants survive cold and other not? Different chemicals in the leaves and stems. Plants that evolved in colder regions make natural anti-freeze.]
Some common questions:
Should I keep the plants covered?
Only if the material you used allows light to penetrate. Covering a plant with a sheet or blanket has two drawbacks. Each point of contact with the leaves and stems is likely to result in damage as the cold transfers through the cloth. And the exclusion of light for more than a day or so will cause the plant to start dropping leaves.
Should I sprinkle the foliage to protect it?
This common agricultural practice is not practical for homeowners. You need continuously freezing layers of ice forming on the foliage through the freezing period (early morning before dawn). Sprinkling the leaves once doesn't make any difference.
Should I pick all the citrus fruit?
Only if you want a bunch of under-ripe fruit. Citrus don't ripen any further once picked, and most varieties aren't ready yet. Your Satsuma mandarins are ripe, but that also happens to be one of the hardiest citrus varieties. Lemons, navel oranges, and others are still tart. I'd be surprised if a couple of cold mornings have damaged the crop. Stripping the tree was appropriate in 1990 and 1998, when we had epic freeze events. A hard frost of a couple day's duration? I prefer to leave them on the tree.
Do I need to protect my rose bushes?
No. Roses are hardy here.
On a more cheerful note, how about some color in the garden in mid-winter?
We are fortunate to live in a gardening climate where we can have color year-around. The afore-mentioned winter annuals can be planted even in the coldest weather, and will continue to bloom into spring or even early summer. Pansies and violas are most popular due to the color range and profusion of bloom over a long period.
There are a few perennials that bloom mid-winter. Examples include bergenia, gazania, hellebores, and red-hot-poker (Kniphofia hybrids). Take a quick walk through the Ruth Storer garden at the west end of the UC Davis Arboretum to get some ideas; it is an all-season resource. On a recent visit the Kniphofia variety called Christmas Cheer was in full bloom.
Certain shrubs give us reliable winter flowers. Examples include the golden bush daisy (Euryops), laurustinus (Viburnum tinus), Oregon grape (Mahonia), rosemary, and the extra-fragrant sweet Victorian box (Sarcococca ruscifolia). Some winter-bloomers with special requirements include camellias and winter daphne. Well worth the effort, but ask before you buy.
We also enjoy the colorful foliage of a number of evergreen shrubs. Cold weather leads to interesting chemical changes within the leaves of certain plants, leading to bright pigments that are less obvious or missing in warm weather. Just part of the background shrubbery much of the year, these stand out in cold months. Examples include the common heavenly bamboo (Nandina domestica) and the purple hopseed bush (Dodonea viscosa purpurea).
One deciduous shrub with late-season color is Japanese barberry (Berberis thunbergii), whose leaves turn bright red in fall and then hang through December. It grows to five feet tall or so. A dwarf cultivar called Crimson Pygmy only grows to 2 to 3 feet tall and wide.
Colorful winter fruit is a bonus of citrus, and the hardiest one is also the most ornamental: the kumquat. Not everyone likes to eat the tart/sweet fruit. The peel is sweet and edible, the flesh is tart. So to eat a kumquat, you pop it in your mouth whole and chew it up. But even if you don't favor the flavor, you can appreciate the abundant bright golden fruit out in the yard. Kumquats are cold-hardy well into the teens, have fragrant flowers in the summer, and the plant has dense foliage and grows upright.
Many ornamental shrubs have colorful winter fruit, including natives such as Toyon (Heteromeles arbutifolia) and Coffeeberry (Rhamnus californica). There are great examples in the Arboretum near the road which goes to Mrak Hall. The non-native heavenly bamboo, mentioned above, also bears red winter fruit with the colorful leaves.
Is it ok to plant these selections now? Sure, if your soil is workable. Digging in muddy soil is bad for the soil structure. But one silver lining to our dry season is that soil can still be turned and proper planting holes can be dug. If not, just hold the plants in the pot until spring. Don't forget to water them if we don't get rain!
For statewide weather data, go to the UC Davis IPM web site and look for the "Weather, models, and degree days" link here. I use the Davis.A station.
Saturday, November 5, 2011
Easy Water Conservation.
Water rates are in the news, and we are getting more interest in lower-water landscaping. It is estimated that 80% of residential water use is outside, with a very large percentage of that due to the lawn.
There are a number of easy ways to reduce your landscape water use.
First is to water correctly.
Water deeply, and as infrequently as possible for the types of plants you have chosen. For example, nothing needs water more often than twice a week during the summer here. Established shrubs and trees can often be watered once a week or less, if they get a thorough watering each time.
Most people could easily reduce their water use by 20% or more just by watering more deeply but less often.
Second is to zone your plants by water need.
You may wish to have a tropical oasis or fern grotto, so put those plants together in one area. You might want a lawn area. Your shrubs and trees don't need to be watered as often as those other types of plants.
Third is to reduce lawn area if possible.
Your lawn, properly watered, uses about 1000 gallons per 1000 square feet each week. And many people apply much more water than needed. Some turf species are more tolerant of infrequent watering, but in nearly any case the lawn is the highest water user in the landscape.
"Form follows function," Louis Sullivan said. Let your landscape form follow the actual use patterns of your family. Lawns are for kids and dogs, and are usually unneeded in front. Put lawn where you will use it, not just where you'll look at it.
Fourth is to choose plants that use less water.
For this article I'll focus on ground covering plants that can replace your lawn and use less water. First is the botanical name, then the common name if there is one. Landscape designers can choose from among Mediterranean plants, natives of South Africa and Australia, California natives, and more.
Herbaceous (soft) ground covers
* Aptenia cordifolia
Popular succulent with red flowers. Rampant! Blooms freely, smothers weeds. Bees love it. Frost turns leaves to mush, but it quickly resprouts in spring.
* Dymondia margaretae
Very tough, low-growing ground cover for dry areas. Little yellow flowers. Some die-out if overwatered. May be damaged in cold winters, but recovers. Excellent between step stones.
* Epilobium species (formerly Zauschneria)
Several species and varieties, ranging from 6" to 2'+. Bright orange-red flowers in late summer through fall attract hummingbirds. Tolerate drought or infrequent watering. Will grow in very light shade or full sun. Cut back when they look rough in the winter.
* Festuca ovina glauca
Blue or Grey fescue
Little tufts of silver grass foliage to about a foot tall. Single plants make a clump. Planted on 6 to 12 inch centers, makes an informal grey meadow.
* Gazania hybrids
G. leucoleana forms spread, have silver foliage, yellow or orange flowers. Clumping types have showier flowers, but don't cover ground as thoroughly--better in perennial borders.
* Lantana sellowiana
Lavender flowers all summer and fall; there is a less-common white form. Grows to a foot tall, with each plant spreading 6 - 10'. Very tolerant of heat and drought.
Cut back in spring to remove frost damage. Also sold as L. montevidensis.
* Rosmarinus officinalis
There are selected forms with spreading habit, and others that are upright. They vary in height (1 - 2 foot +), depth of blue flower color. All can be used in cooking.
* Sedum confusum
Dense, slow-growing succulent with shiny yellow-green leaves and showy yellow flowers. Great for edging; mix with grasses, use in pots, around stepstones. Takes sun or moderate shade, drought or average watering.
* Sedum spurium
Dragon's Blood sedum
Very low succulent grown for attractive reddish-bronze leaves. Tolerates sun or some shade; average watering or drought. Color intensifies in winter. 'Tricolor' has leaves that are white, pink, and green.
* Zoysia tenuifolia
Very dense, interestingly lumpy grass ground cover with needle-fine leaves. Dormant (brown) in winter. Very tough.
Vines that are planted as ground covers.
These are especially drought tolerant.
* Sollya heterophylla (fusiformis)
Australian bluebell creeper
Small, with dense, tiny, shiny leaves. Can be used as a ground cover. Grows slowly to about 6' tall when supported; 1 - 2' as a ground cover. Nodding blue flowers in summer; 'Alba' has white flowers. 'Boddy's Choice' is a very slow-growing type grown as a shrub or ground cover. Quite shade or sun tolerant, will grow under Eucalyptus trees.
* Trachelospermum asiaticum
Nearly always grown as a ground cover. Hardly ever flowers; grown for shiny leaves and exceptional durability. Can be tied up as a vine, but doesn't twine.
* Trachelospermum jasminoides
Super fragrant flowers in May and June. Tolerates heat, cold, sun, shade, poor soil, drought or watering.
Shrubby ground covers
There are many woody plants that spread across the ground, making a shrubby ground cover. These tend to be two to three feet high.
* Artemisia 'Powis Castle'
Vigorous spreader with silver, ferny foliage. Extremely tolerant of heat, drought; ok in partial shade. Leaves have a strong medicinal scent. Completely shades out weeds. Can cover quite an area!
* Ceanothus species
Several low spreading varieties are used as ground covers. Attractive shiny leaves; pretty blue flowers in spring. Ground cover forms range from a few inches to a few feet tall, spreading several feet. Don't plant where they'll have to be pruned. Water deeply and very infrequently in summer. California native.
* Euonymus fortunei 'Emerald Gaiety'
Low grower creeps along the ground, or can be clipped as a shrub. Very tough, tolerant of shade or sun. Flowers aren't noticeable. White portions turn pretty pink color in winter.
* Mahonia repens
Shiny leaves, yellow flowers, shade tolerant. Slow to get going, but persistent and tough.
* Ribes viburnifolium
Catalina perfume, Evergreen currant
Will grow in considerable shade. Spreads steadily to make an attractive ground cover. Fragrant foliage. Very small light pink flowers in winter attract hummingbirds; red berries attract songbirds. California native.
How to do it.
You will need to kill out your grass somehow first. You can spray with an herbicide, or cover the area with black plastic for several weeks. Get your turf species identified since some grasses can be persistent and troublesome, especially bermudagrass. The plants listed don't need any special soil preparation. Rototilling will make planting easier. But you can just dig individual holes for the small plants.
Watering of the new plantings can be done with your lawn sprinklers, but you will water far less often. Or you can convert your system to drip irrigation. You may want to ask a landscape contractor for help if you do that.
Unplanted areas can be covered with a thick mulch to retain moisture and prevent weeds. Any bark or compost product can be used. Local rock yards can deliver bulk quantities at a reasonable price.
You need to do a little math to order the right amount of mulch. For two inches of mulch on 100 square feet, you need 16.7 cubic feet (100 divided by 6 = 16.67 cubic feet). There are 27 cubic feet in a cubic yard.
Green is good, but green lawns are high water users. So reducing your water consumption often begins right in the front yard, by choosing water-thrifty plants.
Wednesday, October 19, 2011
From the Davis Enterprise, October 28, 2004
Click here for a newer article.
Bulbs have got to be the easiest things we plant in the garden, with the highest bloom:effort ratio. Dig a hole, stick 'em in, cover with soil, and water. The rains come along and do the rest. A few weeks later, up they come--growing and blooming without any more work by you.
Some technical terms.
'Bulb' is a generic term for modified, swollen stems. A true bulb has a set of overlapping, fleshy leaves, usually surrounded by dry, papery skin that protects it from drying. Cut a true bulb in half and it'll look somewhat like an onion on the inside (it'll also be useless after you do this!). Corms, rhizomes, and tubers are other modified stems that are sold as 'bulbs'. The primary function of each is to store food and some water, and each has one or more growing points to start new plants.
Bulbs are perennials, meaning they bloom again after the first season. Some repeat for a few years; others spread for many. Most are cold hardy. Subtropical types (paperwhites, freesias) need winter protection in colder climates, which is important to know if you are sending them as gifts.
How do you plant them?
It's so easy, even a child can do it. In fact, since it's down at the ground level and we are old and stiff, it might be better if a child did it. And bulb planting is a great thing to do with kids; it's nearly impossible to make a mistake.
--Dig a hole a little more than twice as deep as the bulb is tall--a 3" daffodil goes into a 6" hole. I generally dig holes wide enough for several bulbs, since a solitary bulb looks pretty lonely the first season, and plant them 3 - 4 inches apart. Exceptions: iris rhizomes are planted only half-buried. Amaryllis should have their necks exposed.
It's not necessary to mix compost in the soil, but the bulbs will grow and increase more quickly if you do. I've done plenty of bulb planting in soil that was too muddy to mix anything into. They'll be fine.
--Sprinkle some fertilizer in the bottom of the hole. It should have some nitrogen and a fairly high amount of phosphorous (those are the first two numbers on the label). Bone meal is popular due to the high phosphorous content, but it is very, very slow acting. Commercial bulb foods are better (specialty vegetable or flower foods are fine, too).
--Set the bulbs a few inches apart. The point goes up (this may seem basic, but it's pretty important!). Some bulbs don't have an obvious point, so look for the scarred area where roots used to be and put that side down. If you really can't figure it out, put it on what appears to be the side. Ranunculus are planted 'prongs down'.
--Cover with soil and water to settle the soil. That's it! Winter rains will take care of the rest.
It is ok to plant low-growing annual winter flowers right on top of the bulbs: pansies, violas, sweet alyssum, Cyclamen, and dwarf snapdragons all make excellent companions. Low ground covers are also great. The bulbs will grow right up through them to make a spring bouquet.
When to plant?
Anytime between September and early January. Tulips and Hyacinths shouldn't be planted until the soil has cooled, meaning after the end of October. If you find the bag of bulbs in your garage in January or February (we get these calls every year ), plant them. They'll still grow and bloom, albeit a little later than normal, and they'll be back on cycle the next year.
Bulb plants continue to grow for several weeks after they bloom, storing energy for the following year. If you cut off the foliage, you weaken the bulb. So let them die down naturally, though you can tie or braid the foliage if you want to look fastidious.
There's no need to dig up bulbs for the following year. If they've been in the ground for several years and are blooming less and less, it may be time to divide them. Or they may be getting too much shade. In either case, just after (or as) they die down is a good time to dig them. Replant them right away, or store them in the garage until fall.
It used to be recommended to put tulips and hyacinths in the refrigerator for 4 - 6 weeks before planting, but this is unnecessary. Just wait until the soil is cool. Pre-chilling WILL make them break dormancy and bloom all at the same time, so if you want your tulips to flower uniformly go ahead. Do NOT put them in the freezer (we get calls .). That kills them.
Some bulbs are planted in the spring for summer bloom--Dahlias, Gladiolus, and others. We plant those from February into the summer, depending on the type.
Which to grow?
Daffodils and narcissus
are the easiest of the bigger-flowered bulbs. At a minimum, they'll repeat their bloom for a few years. Some varieties will multiply, giving more flowers every year.
A note about the names: all are members of the genus Narcissus. Those with a single large flower (usually with a trumpet) are called daffodils. Those with small flowers in clusters are called narcissus. The fragrant ones with pure white blooms in early winter are paperwhites, a type of narcissus; there is a yellow form and another called the Chinese sacred lily in this category. Europeans call the whole group 'jonquils', but we use that term for a particular, small, fragrant narcissus. Confusing, eh?
Some good daffodil choices:
- February Gold (short, very early dwarf trumpet; spreads freely)
- Fortune (orange/yellow, spreads vigorously)
- Flower Record (white with orange cup)
- Ice Follies (white with pale yellow large cup; spreads vigorously)
- Mt. Hood (ivory white)
- Salome (pink, sort of)
- Spellbinder (yellow with white trumpet--striking!)
Good narcissus choices:
- Pheasant Eye
- Yellow Cheerfulness
- Miniatures: Baby Moon
- Tete-a-Tete (one of the best!)
'King Alfred' was once a variety of large, yellow trumpet daffodil. It is now a generic name for that type; Unsurpassable and Early Splendor are newer, more vigorous varieties that will repeat and increase somewhat.
are very easy--both the large-flowered bearded types (grown from rhizomes) and the Dutch irises grown from bulbs. Not generally the most attractive garden plants, but worth the space for fragrance and cutting. There are also cute miniature types which bloom very early, and other species which can grow standing in water. A diverse group.
Tulips, hyacinths, and crocus
will bloom very nicely the first spring. The trick to getting them to bloom in subsequent years is to plant them where they won't get watered in the summer. Tulips with minimal summer water will repeat, though the flowers will be smaller, and hyacinths will increase. These latter have powerful fragrance reminiscent of Grandma's perfume. Giant Dutch crocus tend to peter out after a couple of years, but the species crocus will increase and bloom -- as early as late January here.
Some species of tulips come from Mediterranean climates similar to ours and will naturalize happily here. Tulipa chrysantha, T. clusiana, and others have miniature flowers on short stems. A half-dozen bulbs will increase to 2 - 3 dozen plants within just a few years. Grape hyacinths share the common name but are an entirely different plant (Muscari). These have short, purple flowers and spread very, very freely. The saffron of commerce is Crocus sativus--like some Mediterranean species, it blooms in the fall, and is easy to grow and increase here (coming as it does from Greece, a climate similar to ours).
Many of these (i.e., small bulbs and flowers) spread to the point of being almost annoying. Cheap, easy, and prolific. Most can tolerate some shade, will spread through flower borders and even into lawns.
Some old favorites just don't get enough winter chilling to bloom again, including Lily-of-the-valley and Snowdrops (Galanthus). Freesias are popular for fragrance, and very successful. The old-fashioned yellow and white forms are most fragrant.
Good 'minor' bulbs for this area:
- Allium (ornamental onions)
- Hyacinthoides (Wood hyacinth)
- Ipheion (Spring starflower)
- Leucojum (Snowflake)
There's no hurry on getting bulbs planted after you buy them. They do their thing with little input from us. They announce the spring with colorful bursts in every hue. These little storage units have everything they need, lying dormant through winter cold or summer drought, ready to expand and grow when conditions are to their liking. What a great adaptation the bulb is--for us!
Saturday, September 24, 2011
Written for the Davis Enterprise, August 25, 2011
Click on any image for a larger version
The first clue that this isn't a traditional California landscape is the branch of the Japanese maple peeking out behind the front gate. The drain channels filled with smooth pebbles and elegant "rain chains" are the next signs of some non-Western influences. Small plantings on the side as you walk around the house use gravel and interesting foliage plants.
Crilly Butler and his family live in a house on a quiet cul-de-sac in one of the newer subdivisions of east Davis. Crilly has visited Japan frequently and considers it his second home, and from the time they purchased the bare lot in 1996 they knew they wanted a zen garden. He invited me to view and photograph the garden this spring.
There are several styles of Japanese gardens. Karesansui is the waterless type, generally using limited amounts of plant material, moss (if possible), raked gravel to symbolize water, and groups of rock and stones. Lanterns and pavilions are often included in Japanese gardens of various types. Bamboo, both in plantings and used in construction material, is an important component. Among the many symbolic meanings for bamboo, I found humility, strength, readiness, resilience, simplicity, and more.
To the first-time visitor to a zen garden, it will seem bare. There are rarely flowering plants, and the seasonal changes are subtle. But the lack of abundance focuses the viewer's attention on those simple changes: the flush of new growth on the Japanese maples, the spectacular but fleeting bloom of the wisteria, the seasonal growth of moss on the boulders. In a more complex garden, these would be less individually notable.
From a design standpoint, I was curious how the garden would integrate in a California-style house (at least the exterior) and landscape, including some typical uses such as vegetables and roses. From a horticultural standpoint, my key question was: how did you confine the running bamboo?
Crilly answered my specific questions via email after my visit. As to my design question, it was clear that the zen garden is the strong visual element and that it was carefully designed to fill the key views from the house and patio. The roses and vegetable garden are in an appropriately sunny location off to the east side, just out of view from the house. The bamboo barrier is shown and described below. Note that it would be possible to use non-running bamboo varieties to avoid the confinement issue. Most clumpers, though, have very dense growth habit and might not provide the "see-through" effect that runners provide.
What was your motivation or inspiration for planting a zen garden?
I used to live in Japan, where I studied the martial art Aikido. I met and married my Japanese wife there 28 years ago. I've always loved my "second country", and deeply admire its aesthetic sense. We patterned our Zen garden after our favorite one, found at the famous Kyoto temple Ryoanji.
Did it replace an existing landscape?
We designed and built our Japanese/Western hybrid home on an empty lot, so we were able to plan our landscaping from scratch. Our Zen garden simply replaced barren ground. I think it's quite an improvement!
What year was the project begun, and when was it completed?
We began designing this garden in our minds as soon as we purchased our lot in 1996. After completing the Western rose and herb garden on the east side of our backyard, we started grading for the Zen garden in 2004, though we didn't actually began work on it until 2008. We finished building the border around it, and laying the gravel, in 2009.
Who helped with your design and installation?
My wife and I designed it ourselves, based, as I mentioned, on the garden at Ryoanji. You have to place the rocks just right, so they look as they should from every part of the yard, no matter what the angle. We used orange road construction cones to represent the three "islands", and over the course of 3-4 weeks, kept moving them around slightly until we were satisfied with their placement. My friend Steve Scott carried the large rocks into the yard in a sling attached to one of his small earth-movers, and helped us position them precisely. Other than that, my son Nicholas and I did all the work ourselves.
Tell us about selecting and installing the rocks.
We looked for just the right rocks for quite some time, but couldn't find any that looked like those at Ryoanji. Then we finally stumbled upon some petrified wood boulders at a quarry east of Sacramento. They were unexpectedly perfect!
Where did you buy your bamboo? Why did you select that species (Temple bamboo, Semiarundinaria fastuosa)?
Steve Scott, who's quite a bamboo aficionado, suggested the Temple Bamboo because of its very erect, tall and beautiful culms. We drove his truck to Bamboo Sourcery in Sebastopol, which is an amazing place. They had over three hundred varieties of bamboo there at the time. We planted them about two feet apart in an L-shape along most of our back fence, with the leg extending out about ten feet along the west side of our yard.
Because this species is quite a runner, I trenched around the planting area four feet deep and six inches wide, which I filled with rebar and concrete to keep the bamboo contained. There's nothing worse than seeing your bamboo growing up through the bottom of your neighbor's swimming pool, and I take being a good neighbor very seriously!
Just to verify: your barrier is a concrete trench 4 feet deep, six inches wide, with concrete rebar at 1 foot intervals. Watering is via drip soakers. How often do you run them? What other maintenance do you do?
I ran schedule 80 pvc underground to one end of the bamboo and installed a drip system using three separate soaker hoses winding through the base of the culms end-to-end. It runs for about 20 minutes three times per week in summer, and much less during the other three seasons.
Since bamboo takes in a lot of its moisture through its leaves, I also soak it down top to bottom with a hose periodically, especially when the humidity has been very low for a while. I fertilize every spring with a good lawn fertilizer mixed with FST, since the concrete probably raises the pH of the soil quite a bit. Every winter I thin out the older culms to make room for new growth. I leave the fallen leaves to decompose, rather than removing them, because of their high silica content, which growing bamboo loves.
Some further notes:
A very important part of this barrier system is the maintenance gap between the hedge and the fence. Rhizomes can grow right over a barrier and root, and can readily grow under a fence. Rhizome growth occurs mostly in the spring, so one seasonal walk (sidle, really) behind the hedge to check for escapees will be sufficient. Barriers can be made from very thick polypropylene (60 ml is best). This installation is much more attractive, in my opinion.
Although a zen garden can use considerably less water overall than a more traditional landscape, due simply to the large area without plants, those that are used tend to be high water users. Bamboo and Japanese maples look best if they are not drought stressed.
Japanese maples have some special preferences here. They prefer acid soil with abundant organic material, so turn in lots of planting compost and soil sulfur at the time of planting. While they can take morning sun, Japanese maples will burn in afternoon sun. Finally, true moss is seasonal in our dry, hot climate. Various ground covers can be used as substitutes.
Crilly Butler is a Senior Information Systems Analyst for the California Department of Fish and Game. He also owns the Davis-based Web development company, Develomation.
Steve Scott (http://stevestrees.com/) is a landscape contractor who specializes in moving large field-dug trees.