IN THE GARDEN IT'S TIME TO PLANT IN VALLEY.

Byline: JOSHUA SISKIN

The moment known as the window of opportunity for planting in the Valley has arrived. From the last days of September through the entire month of October into the first days of November, we can do no wrong when it comes to planting our gardens.

This is also the moment to think about three horticultural projects which are especially suited to the fall months: lawn renovation, bulb planting and bare-root planting of trees and roses.

Let's start with the lawn. If you have crabgrass in your lawn, now is the time to kill it with contact herbicide or scrape or dig it out with a sharp-edged hoe or shovel. Many people use the word ``crabgrass'' generically, and they mean to include by it almost any weed they see growing in their lawn.

True crabgrass, however, is distinctive among lawn weeds in its capacity to completely overtake a lawn in the course of one summer and then die back completely in the winter. Crabgrass grows in bright green clumps and does not have the rhizomes and runners of perennial grasses such as Bermuda and Kikuyu that are typically mistaken for crabgrass. In terms of its color, no lawn outshines an expanse of crabgrass in midsummer, and if it did not die each winter, it would make an excellent lawn substitute.

To keep crabgrass from coming back next spring, you will have to reseed or resod the areas where it grew this year. After you have mowed your new lawn twice, you should apply a pre-emergent herbicide that will prevent crabgrass seeds left behind from germinating. To be safe, you should make another pre-emergent herbicide application in late January, just before spring - which comes to the Valley in February - begins.

In the course of a few years, Bermuda and Kikuyu grasses can also overtake a lawn. Before spraying them out, however, you may want to consider leaving them alone. From a money-saving perspective, this would be a wise decision. Not only will you save the expense of redoing your lawn, you'll save money on future water bills as well.

The downside of Bermuda and Kikuyu is that they produce a layer of thatch and go dormant, turning brown, in cold weather. It is customary to use a vertical mower or dethatching machine, available at most equipment rental yards, in October to slice through and chop up the thatch. If we have a warm winter, your lawn could regrow and remain green all winter long. Alternatively, you could overseed with winter rye grass following the dethatching procedure to ensure that the lawn stays green until the Bermuda or Kikuyu begins growing again next spring.

Bulbs that come back

Fall is bulb-planting season, but before you bury your bulbs, make sure that your soil drains properly. Planting bulbs in compacted soil will result in the bulbs rotting before they send up shoots and flowers. In the Valley, if you want bulbs that will come back year after year, plant narcissus, jonquil, daffodil, freesia, leucojum, sparaxis, amaryllis or Spanish bluebells. Humboldt lily is a California native bulb that reblooms reliably each summer without any water other than winter rain.

Bare-root savings

Bare-root planting of roses and fruit trees, done in late fall and winter, is a money-saving practice. Bare-root roses and fruit trees, whose roots are packaged in wood shavings, generally cost 50 percent to 75 percent less than those sold in containers. The selection of bare-root fruit trees is also much more diverse than the selection of container grown trees. Bare-root roses and fruit trees should be available in nurseries and garden centers by the first week of October. In the Valley, roses grow best in half-day sun, while fruit trees need six to eight hours of Valley sun to produce good crops.

TIP OF THE WEEK: Thanks to Ron Strong, retired L.A. Parks supervisor, for his identification of the Lake Balboa cherry trees as Prunus serrulata ``Pink Cloud.'' You can order bare-root ``Pink Cloud'' trees from Orange County Nursery in Garden Grove, www.ocnursery.com or [phone]. The nursery, which offers a wide variety of fruiting and flowering trees, does have a $300 minimum order, so you might want to get together with family, friends and neighbors.