IN THE GARDEN GARDENERS' MINDS IN FULL BLOOM.

Byline: JOSHUA SISKIN

When you are a student of plants, you learn wherever you go. Just the other day on Wilshire Boulevard in West Los Angeles, I saw the most stunning display of two plants, alternating as they both spilled over a low black marble wall. One was a purple heart (Setcreasea purpurea) and the other was a lotus vine (Lotus maculatus). The large violet leaves of the purple heart contrasted perfectly with the green snowflake chains of lotus vine foliage, and both grabbed my attention against the black marble backdrop. As a bonus, purple heart flowers in pink, and lotus vine have orange blooms that look like the beaks of tropical birds.

On a recent visit to Palm Springs, I saw some horticultural sights - ranging from plant substitutions to grass and ground cover - that could provide valuable lessons for Valley gardeners.

As you may know, oleanders are dying everywhere from Palm Springs to Pacoima. The problem is bacteria that inhabits oleander sap and is spread from plant to plant in the saliva of the glassy-winged sharpshooter, a species of leafhopper insect that also causes problems in California's almond orchards and vineyards.

In Palm Springs, as replacement for some of the dying oleanders, giant thevetia (Thevetia thevetiana) is being planted. This oleander cousin has a shiny, almost succulent leaf and buttery yellow flowers. Because it may be damaged by frost - and size is the best defense against cold weather - plant the largest specimens you can find.

Another widely used plant in Palm Springs is crown of thorns (Euphorbia milii). This poinsettia relative has red, pink or yellow bracts that are on display 365 days a year. It also may be damaged by a cold snap, but is definitely worth the risk. The species grows up to 5 feet tall, while the dwarf, mounding hybrids, such as Apache, do not exceed 18 inches in height.

If you are frustrated with the maintenance that ground covers require, consider decomposed granite, a highly popular ground cover substitute in Palm Springs. Decomposed granite - or DG - is a coarse type of sand that compacts when wet and tamped down. Put a 2-inch layer over the soil and compact it with a water-filled drum, available at any rental yard.

Install individual drip emitters or bubblers next to the shrubs or perennials that are shown off to excellent effect against the tawny background of the DG. From both design and water-saving perspectives, it makes sense to consider the DG alternative.

The lawns in Palm Springs, almost without exception, consist of fine-textured hybrid Bermuda grass. Hybrid Bermuda will remind you of the grass on putting greens. Bermuda grass is tougher than the tall fescue (Marathon) commonly used for Valley lawns. The downside of Bermuda is its winter dormancy, when it turns the color of straw. In the Valley, fescue lawns, within five to 10 years of planting, are nearly always taken over by Bermuda or kikuyu grass. This is not necessarily bad since these aggressive grasses are not as water-needy as fescue. Both Bermuda and kikuyu go dormant, however, in winter. Usually, they are overseeded with annual rye, which grows until warm weather returns in the spring. Annual rye, however, is a fast-growing, weak grass that mats down and dies in spots from fallen leaves and heavy rain.

In Palm Springs, however, perennial rye is used to cover the dormant hybrid Bermuda lawns. Perennial rye is a bit more expensive, but far sturdier, slower growing, darker green, more attractive, and easier to maintain than annual rye.