San Fernando Valley dwellers may lament the small number of trees and shrubs whose leaves turn color this time of year, especially if they grew up in New England, where the autumn foliage display is a tourist attraction unto itself.
But there is a select number of trees and shrubs that do offer fall color for Valley gardens and, as it turns out, all of them are easy to grow and parsimonious when it comes to water use.
Chinese pistachio (Pistacia chinensis), a deciduous species, possesses leaves that change to every shade of yellow, gold, burgundy and red before dropping off as winter takes hold. Upon reaching maturity, the Chinese pistachio develops a perfectly domed canopy, a shapely aesthetic asset in any season.
Another tree worthy of consideration for its kaleidoscopic fall foliage is the Chinese tallow tree (Sapium sebiferum). A few years ago, this species was planted as a street tree in Sherman Oaks along Ventura Boulevard east of Woodman Avenue, much to the delight of passersby this time of year.
Not only does the tallow tree keep to a manageable size, but it is replete with heart-shaped leaves that are presently shimmering with all the colors of the rainbow. Bear in mind that this relative of the poinsettia contains sap that is somewhat allergenic, and so its pruning is best performed in long sleeves and gloves. This should be done frequently when it is young to offset its tendency to lean in one direction.
The liquidambar is on everyone’s list of fall color trees, but with at least one serious reservation: Its roots are a threat to water lines, sidewalks and surrounding asphalt and concrete surfaces. Even where pipes and pavement are not a concern, the garden itself is compromised since only sparse ground cover, if that, can grow in proximity to a mature liquid-
ambar tree (Liquidambar styraciflua).
If you have room to spare, investigate its many varieties before selecting the one with the colors you like best. Although unrelated to maples, liquidambars have maple-leaf shaped leaves and, like Eastern maples in the fall, some varieties have strong burgundy tones.
Where shrubs are concerned, three closely related groups – barberries, mahonias and nandinas – take center stage in the fall color arena. The Japanese barberry (Berberbis thunbergii) is available in many varieties, ranging from 6-foot-tall background or hedging types such as ‘Sparkle’ and ‘Rose Glow’ to 2-foot ‘Crimson Pygmy’ dwarfs.
Mahonia, commonly known as Oregon grape, has shiny and spiny leaves, yellow flowers and edible, if insipid, purple fruit that attracts wildlife. Several varieties are available, from gangly, arching bushes to ground covers.
Most people are familiar with nandina, or heavenly bamboo, even if they don’t know its name. It has soft, delicate, finely divided foliage and no drawbacks except for sensitivity to alkaline soil and hot sun. Many colorful varieties exist, but I am partial to ‘Gulf Stream,’ which has a dense growth habit and stays between 3- and 4-feet tall.
Chinese flame tree (Koelreuteria bipinnata) does not have colorful foliage but it does have unusual magenta seed capsules, with an appealing papery texture, that brighten up the garden. This is a moderate-sized tree that does not exceed 50 feet in height. It grows in Sherman Oaks on Ventura Boulevard just east of Hazeltine Boulevard. Its summer flowers are large golden panicles that are mildly perfumed.
This is the time of year when plants begin to go dormant. As they settle down to sleep, it is appropriate to tuck a nice warm blanket of mulch around them.
Start by soaking the ground well and applying a 2- or 3-inch layer of mulch. This can be made from straw, shredded newspaper, stable cleanings or leaves composted with steer manure. If you do so, you will not have to water your planters more than once a week, if that, for several months, depending on the weather and the types of shrubs and perennials involved.
Nearly all woody shrubs, natives and bulbous perennials can go from now until mid-February, when the Valley spring begins, without supplemental irrigation, as long as we have average precipitation during the winter.
In order to economize on watering, it is essential to separate sprinklers in planters from those in lawns in a systematic way. If a single watering circuit includes both planter and lawn areas, you will either water the planters too much or the lawns too little.
Incidentally, a lawn that is properly aerated and fertilized should not need to be watered more than twice a week during the fall season. If your Marathon or tall fescue lawn starts to turn yellow as the weather cools, fertilize with urea and iron sulfate to keep it green. Take care that the iron sulfate does not get scattered on sidewalks or hardscape surfaces since it will stain them orange.
Tip of the week
At this time of year, you may see fruit on your olive tree and, if so, consider preparing it for consumption. Green and black olives come from the same tree. Green olives are the unripe fruit. When left on the tree, green olives turn black as they ripen. Olive trees should be planted several inches above grade to ensure perfect drainage for their roots. Olive trees should not be planted in a lawn because they are prone to a lethal Vercillium soil fungus that is activated by the copious watering that lawns require.
To cure green olives, soak them in a lye or sodium hydroxide solution (1 tablespoon of lye per quart of water) for 12 hours, drain, then soak in fresh lye solution. At least two but perhaps three soakings will be needed. Softness of the olives down to the pit is an indication of their readiness. Finally, soak them in cold water for six hours and then change water daily until water color changes from red to pink.
To cure black olives, soak them in a solution containing 4 tablespoons of salt per quart of water. Change the solution once a week for three weeks. Then place the olives in a marinade consisting of 11/2 cups white wine vinegar, 1 tablespoon salt dissolved in 2 cups water, 1/2 teaspoon dried oregano, 3 lemon wedges and two garlic cloves. Of course, you can alter the marinade solution ingredients to your liking.
Put a 1/4-inch layer of olive oil over the top and marinate for no more than a few days.
In the above treatments, make sure your olives are completely submerged as they soak. Do this by placing a heavy plate over the surface of the curing or brining solution.