WEEDS MAY MASQUERADE AS GRASS.

Byline: Joshua Siskin

Each summer, around the corner from my house, a delicate, white funnel-shaped flower pops up in great profusion amid a bed of English ivy. Each summer, a neighbor's lawn that is dull and drab most of the year suddenly turns a brilliant green. Each summer, another lawn a few blocks away begins to glow with a lush and silky luster unmatched by any grass on Earth. With weeds, appearances can be deceiving.

The white flower growing in the English ivy is attached to long green shoots of wild morning glory (Convolvulus arvensis). Wild morning glory is also known as field bindweed on account of its growth habit. It binds itself to whatever crosses its path, tightly wrapping itself around the stems of anything that grows. Bindweed flowers are either white or pink.

Since bindweed grows among plants that you treasure, you will have to approach its control with caution. A common practice is to don rubber gloves and dip a sponge in Round-Up or a similar product. Sponge the herbicide on the offending wild morning glory and the plants in which the bindweed was intertwined will not be tainted.

My neighbor's generally unremarkable lawn that turns greener the hotter it gets consists mainly of crabgrass (Digitaria sanguinalis). Crabgrass grows best in compacted, heavily watered lawns. No weed grows faster during the summer. If you have a few small patches of crabgrass in your lawn, be wary. In a year's time, your entire lawn could be engulfed by it.

Crabgrass is the most deceptive of lawn weeds. From a distance it cannot be noticed. Even up close, to the unknowing eye, it is invisible, especially in a lawn that has been green and healthy. However, closer examination reveals thick tufts of a grass whose blades are twice as wide as those of tall fescue, the most popular lawn grass in California. (Marathon and Medallion are tall fescue cultivars.)

The saving grace of crabgrass is its growth habit. Crabgrass always dies in the winter, first turning purple and then brown. There are plenty of chemicals on the market to control crabgrass. The recommended practice is to apply pre-emergent chemicals in late winter and early spring since the seeds deposited by last year's crabgrass germinate as soon as the soil warms to 60 degrees. Some bags of fertilizer have these chemicals mixed in so that you can green up your lawn and keep crabgrass out with a single application. Alternatively, you can spray existing crabgrass with contact, post-emergent chemicals.

Good cultural practices such as regular fertilization and lawn aeration will prevent crabgrass in the first place.

If you see a lawn with an uncanny, too-good-to-be-true, edenic luster - as I have seen for years in my own neighborhood - you are probably looking at nutgrass, not really a grass at all.

Also known as yellow nut sedge (Cyperus esculentus), nutgrass is a relative of papyrus (Cyperus papyrifera) and umbrella plant (Cyperus alternifolius), both of which are moisture loving plants, the latter often found in backyard water ponds. In the opinion of some, nutgrass is the most pernicious weed in North America. It grows from obdurate nutlike tubers that defy deracination. There are chemicals for killing nutgrass as well. However, because of its indestructible nature and undeniable beauty, the idea of a nutrias lawn is quite appealing. The downside of nutrias is its dormancy; it dies back completely during the winter. A nutgrass that stayed green all the time would make the ultimate in easy-care lawns.

In truth, ``weed'' is an arbitrary term. The lantana that flowers in orange and gold during the hottest days of August and September - and is a favorite long-blooming shrub of many gardeners here - is considered an invasive weed in Hawaii. Its fleshy purple-black berries are eaten by birds which drop its seeds - that eventually sprout and grow into new plants - all over the islands. Trumpet bugle (Ajuga reptans) is a highly prized and short-lived ground cover in our area but, in wetter climates, is a weed. Other ornamental plants in our area that are labeled as weeds elsewhere include butterfly bush (Buddleia), baby's breath (Gypsophila), and sheep's fescue (Festuca ovina).

It depends on your perspective.

Garden Tip of the Week

Fall bulb planting is only a month away, and now is a good time to order them. For a change of pace, consider fragrant daffodil, tulip and hyacinth varieties. Plant them near your front door or kitchen window to take full advantage of their scents. A free catalog of these bulbs may be ordered by calling Breck's Bulbs toll free at [phone] or you can access them online at www.myseasons.com

CAPTION(S):

photo, box

Photo:

Bulb plants, such as this ``Rembrandt'' tulip, are fragrant and beautiful in a garden or pot.

Box: Garden Tip of the Week (see text)