Chinese arborvitae (Platycladus orientalis)

Two gardening questions received by e-mail toward the end of 2001 may stimulate creative horticultural thinking for 2002.
Q: I want to plant a garden but cannot afford to spend a lot of time or money taking care of it. Any suggestions?
– Gladys Albert, West Hills
A: The ultimate low-maintenance garden might be modeled after some of the famous gardens of Japan that contain no plants at all. Japanese gardens may consist of nothing but large rocks or boulders surrounded by pea gravel. The rocks represent the islands of Japan and the gravel represents the surrounding ocean. The only maintenance involved is occasional raking of the gravel; patterns created in the gravel represent waves or currents of water.
Sparsely planted Japanese gardens may consist of rocks, gravel and junipers. Once a mainstay of Valley gardens, the juniper has fallen out of favor over the years due to its lack of flowers and, in the opinion of some, prickly and standoffish character. Yet a collection of junipers can provide everything a conventional garden offers and more. If you are looking for color, there is plenty to be found in a juniper garden. There are all shades of green and blue and variegated varieties whose scales (leaves) are splashed with gold.
For a layered look, junipers are definitely the plant of choice. There are juniper shrubs that grow to a height of 6 feet and ground cover junipers that are less than a foot tall. In between, you can find junipers of any stature. The Tam juniper (Juniperus sabina “Tamariscifolia”) was at one time an exceedingly popular plant for hillsides. Growing to about 3 feet in height and spreading to more than 10 feet, it offered a solution to erosion-plagued slopes where irrigation systems were problematic. Actually, Tam junipers showed themselves, in the course of time, to be somewhat disease prone; the “Broadmoor” juniper proved to be a longer-lived alternative.
A principal selling point of junipers is their drought tolerance. Once established, a twice-monthly soaking in the hottest weather should be enough to keep most varieties healthy. If possible, drip irrigation or soaker hoses should be used to water junipers since their foliage, when wet, is highly susceptible to fungus diseases.
There are also columnar juniper trees which can grow as high as 20 feet. These trees resemble smaller versions of Italian cypresses, which are their botanical cousins. Columnar junipers in both green and blue-gray are available. For counterpoint in a garden of junipers, plant a few arborvitae (Thuja and Platycladus species). These gum-drop shaped yellow-green shrubs are also scaly but provide a rounder, softer look than that afforded by either the juniper or the cypress.
Q: Will my poinsettia survive if it is transplanted into my garden?
– Tim Hutchinson
A: In the Valley, it seems that there are a few established poinsettia bushes growing in almost every neighborhood. These poinsettias are quite visible since they are of a good size, usually between 4 and 6 feet in height.
All the poinsettias I have seen growing outdoors in the Valley are adjacent to walls of houses. I have never seen a poinsettia growing in the middle of a Valley garden. As a native of tropical Mexico, the poinsettia needs protection from our cold, and occasionally freezing, winter nights. Planted outside the wall of a house, a Valley poinsettia would benefit on a cold night from any heat leaking through the wall. In addition, heat the wall absorbed during the day would radiate in the direction of the poinsettia at night. If you could plant your poinsettia under the eaves of a roof, so much the better. Heat absorbed in the ground during the day will be prevented from escaping into the atmosphere by the eaves at night, benefiting any plants growing below.
By the way, you should not plant your poinsettia outdoors until March.
TIP OF THE WEEK: This is the time of year to propagate junipers and cypresses. Detach 3- to 6-inch shoots and insert them into a mixture that is nine parts perlite or sponge rock and one part peat moss. Prior to insertion, dip the base of each cutting in root hormone powder, available at most nurseries. You must be patient with these cuttings as rooting may not begin for another four to six months.