A popular notion in environmental design and landscaping today is that the “job” has to look “finished” right after the installation is completed. Let’s take a look at that idea and examine it under the light of the goals of Xeriscape.

First of all, some definitions. “Xeriscape” refers to the conservation of water through creative landscaping. ?EUR??,,????'??Job” refers to the entire project; conceptual design, workings drawings, specifications, budgeting, material selection, site preparation, timing, construction, and presentation to the owner or client. “Finished” means established or mature, as characterized by the subtle polish we sense when we stroll through an old, well-tended garden.

As far as the landscape professional is concerned, the job is finished when the final payment is made and it looks finished when (all too often) oversized plants are crowded together to give that ?EUR??,,????'??full” effect. As far as the plants are concerned, large or small, it is only the beginning As far as Xeriscape is concerned, the plants have to get established and thrive under a regime of water conservation. This is where we start to see the problem.

When a drought tolerant shrub is planted from a five-gallon, 15-gallon or larger size container, we are asking that plant to thrive and grow after being removed from a nursery culture that pampered it for three to five years. We require that it grow in a possibly warmer or cooler climate than its nursery environment, survive having its roots disturbed, dried-out (even damaged) during planting, and get used to much less water than it was raised with. Perhaps we even ask it to get established in the summertime, a season, when most construction and planting is done and yet most drought tolerant plants are semi-dormant, (certainly not actively growing). And finally, after all of that, we expect these plants, whose top growth sometimes far exceeds a proportionate root ball, to become quickly established.

This problem is magnified on slope planting, where both trees and shrubs are meant to act ultimately as erosion control and slope stabilization.

This problem is magnified on slope plantings, where both trees and shrubs are meant to act ultimately as erosion control and slope stabilization. The mature container plants (5’s, 15’s and larger) are planted on slope ratios, of 1 1/2:1 or 2:1, and watered with overhead irrigation in a desperate attempt to provide adequate water for the oversized plants. The water promptly runs off the steep, compacted slopes. The resulting cover consists of shallow-rooted, fairly unstable trees and shrubs, which never really become established. They require frequent irrigation and their instability may even contribute to slope failure in the event of a serious winter downpour or wind storm.

By contrast, a tree, shrub or groundcover planted as a smaller size, with a proportionate root-to-foliage ratio, and planted in the proper season, will become established much more quickly; produce a deeper root system; require much less water to thrive; perform much more effectively as the desired erosion control and usually, far outpace the larger plants in only two or three years.

But, you say, “Our clients want a finished look now” (there is that word again!). By employing Xeriscape technique, you can achieve that desired look. Utilize plenty of specimen size trees and shrubs grouped with showier islands of color at entrances and key visual landscape points where good horticultural conditions exist. Then select some drought tolerant plants in one gallon (shrubs) and two or five gallon (trees) for the less viewed planters, parking lots, and mow strips. On slopes, go one step further?EUR??,,????'??? smaller! Plant the appropriate drought tolerant plants from flats, liners, four-inch pots, deep plant sleeves or one-gallon sizes, preferably in the cooler, fall season. In addition, copy nature’s plan with a “succession” planting scheme, by utilizing fast growing, showy, flowering herbacious, perennials in front of slower, long term shrubs and trees for immediate effect. (Refer to the April 1986 issue of Landscape Architect and Specifier News, for the article “Space and Xeriscape.”)

As specifiers of plant rnaterial for our clients, we have the opportunity and the responsibility to select the appropriate plant type, spacing and size to insure a thriving, healthy, attractive, and drought tolerant Xeriscape, that will have that “finished” look for years to come. The most important question is...“How big does it get?”...not, “How big is it now?”!!!

Mike Evans is co-owner of the Tree of Life Nursery, wholesale growers of California native plants in San Juan Capistrano. He has served on the Xeriscape Committee in California since its foundation.