IN THE GARDEN SPIDERWORT EASY TO APPRECIATE, HARD TO BANISH.

Byline: JOSHUA SISKIN

For years, I have been at war with the common spiderwort (Commelina communis). Although it is, at times, a bitter battle, I must confess to stopping and stepping back, every now and then, simply to admire the beauty of my rapacious ground cover foe.

Spiderwort leaves are diamonds of silky green, arranged alternately along the stem, and spiderwort flowers are as true blue as any you will see. Also known as Asiatic dayflower, since it originates in the Orient and its blooms last but a single day, the floral splendor of this ground cover is evident from summer until fall.

Unmolested by pests of any kind, its sole nemesis is freezing weather, which turns it into mush. The Asiatic dayflower is considered a weed because of its tendency to appear suddenly as an unwanted guest, unannounced and unplanted, in moist flower beds. You see a little piece of it growing and barely pay it any mind until, a few weeks later, it has smothered everything in the vicinity. It propagates itself from seeds, tubers and stem pieces, which, if scattered over the surface of a planter bed, will root wherever their nodes (stem joints) touch the earth.

You can imagine my surprise when, at the nursery the other day, I spotted a plant with foliage closely resembling that of the Asiatic dayflower except for one crucial difference: it was variegated with broad blotches of pink and white. Upon closer inspection, it appeared that all the new leaves were pink, that they faded to pink and white, and finally became mostly green, retaining some splotches of pink and white, as they aged.

The name of this startling plant is Tradescantia ``Blushing Bride,'' a hybrid of two spiderwort species. This new introduction could play a vital role as a ground cover in shade gardens. The leaves of many variegated plants lose their distinctive coloration when planted in too much shade, but the leaves of a select number of variegated plants, including ``Blushing Bride,'' turn completely green, instead, when grown in too much sun.

The best exposure for ``Blushing Bride'' is bright shade, the sort of environment you would expect to find under a tall, leafy tree or on the shady, eastern or northern side of a low wall or fence. Despite an ardent search for something more colorful than ivy or ferns, ground cover selections for shady areas have been limited to mauve-blue periwinkles (Vinca Major and Vinca Minor) and mauve-violet bellflowers (Campanula poscharskyana). A ground cover with pink and white variegation that could hold its own in the shade would be a welcome addition to the shade gardener's plant palette.

Not only has this winter been one of the wettest in history, but also it has included some of the coldest temperatures in recent memory. In Woodland Hills, I saw ``Red Apple'' iceplant disappear from one planter bed after another during several cold nights in January and, in Sylmar, ivy geraniums turned black following a frost.

If I had been wise, I would have planted Centradenia grandifolia instead. Only recently did I discover this special ground cover, a relative of the princess flower (Tibouchina), and have witnessed it produce clusters of rose-colored flowers all winter long. Centradenia's leaves are flushed red and it grows well in the full sun of winter but, from what I hear, will appreciate some sun protection when summer comes. It is not only an excellent ground cover subject, but also spills nicely out of flower pots and hanging baskets as well. Centradenia is hardy down to 20 degrees Fahrenheit.

TIP OF THE WEEK: After a rain, take note of water puddles in your lawn and garden. This is a quick way of evaluating areas where drainage is inadequate. Then, once the ground dries, you will know where to take remedial action by adding soil amendments, digging dry wells, or constructing French drains, depending on the severity of your drainage problems.