WHEN LANDSCAPING YOUR YARD, TAKE COVER.

Byline: JOSHUA SISKIN

One thing's for sure: It is better to stay with one ground cover throughout a landscape than to plant many different types in a hodgepodge manner. Ground cover is really supposed to serve as a demure, understated underplanting to more important perennials, shrubs and trees.

In a mature landscape, there is not much truly bright sun that reaches the ground. Where gazania and rosea ice plant may have once flourished when trees were small, there is not enough light later on to sustain such ground covers, much less bring out their flowers.

Two ground covers that come to mind for part-sun situations are dwarf periwinkle (Vinca minor) and Serbian bellflower (Campanula poscharskyana), both of which have blue flowers. Actually, the pinwheel-flowered periwinkle can take more shade than the bellflower but both are noninvasive and shallow-rooted, making them easy to control.

One of the most popular plants for part-sun, part-shade situations is star jasmine. This vining plant is sometimes used as a ground cover, even though it usually ends up 8 or 10 inches tall. Unlike the dwarf periwinkle and the bellflower, star jasmine will not allow more delicate perennials - especially those in the 1- to 3-foot tall range - to grow in its midst; it should only be planted as a complement to woody shrubs and trees.

For pure shade situations, there are two ground covers, in particular, that deserve attention. One is baby tears (Soleirolia soleirolii) and the other is dwarf mondo grass (Ophiopogon japonicus ``Nana''). Baby tears will require regular maintenance since it readily grows up into every sort of nook and cranny if given half a chance. Dwarf mondo grass is probably the easiest to maintain, and its deep green clumps engender a feeling of happy calm.

There are a variety of succulent plants that do well as ground covers in full sun to semi-shaded exposures. In this category, my all-time favorite selection would be Sedum confusum, an underused and vastly under- appreciated succulent with glowing, silky emerald green leaves. It has golden flowers in late winter or early spring but you will grow it for its foliage and the ethereal feelings that it engenders.

Red apple, named for its cherry red flowers, is a popular succulent ground cover that can be problematic. If your soil is poor in iron, the foliage will turn yellow. It also seems to tire out quite rapidly if soil drainage is imperfect or if it is overwatered.

TIP: Laraine Reisner of Woodland Hills recommends a simple strategy for dealing with a common Valley garden pest. ``I learned a simple solution for an annoying problem,'' she writes. ``Every year, the fruit from my orange and tangerine trees was being devoured by squirrels. A friend told me to take the CDs that come in the mail as advertisements and hang them from the trees on long pieces of rope. I discovered it deters the squirrels because of the shiny metal and movement. My trees are now full of fruit and I guess the squirrels have gone to a neighbor's house.''