WEED POSES THREAT TO LAWNS; WEED PUTTING LAWNS AT RISK.

Byline: Michael Coit Staff Writer

A new green menace has crept onto golf courses, fields and lawns across Southern California.

Broad swaths of tall fescue, Bermuda and perennial ryegrass that define the San Fernando Valley region's suburban lifestyle are under an unprecedented attack from a particularly virulent weed - the green kyllinga.

``There are other weeds - but nothing that bad,'' said Jeff Hicks, assistant golf course superintendent at Woodland Hills Country Club.

The grasslike plant is a stealth pest, sending out extensive underground stem systems that leave turf soggy and unsightly and choke ornamental plantings.

``It's creeping into this area. It's a patch in one of our tees,'' said Mike Undem, golf course superintendent for Knollwood Country Club in Granada Hills. ``It looks like turf and it's hard to see until it's established. You're fighting it then.''

The Asian native is becoming a major problem in California, say weed scientists doing research on green kyllinga. No single control, whether herbicide or landscaping practice, has proven successful in eliminating the weed from either turf or ornamental plantings.

``A lot of times you will find a silver bullet that will kill it, but with this weed we haven't found it yet,'' said Dave Cudney, a University of California, Riverside, weed scientist. ``There are ways we can reduce it. We don't have ways to eliminate it.''

Cudney is scheduled to make a presentation on green kyllinga Tuesday during the 52nd Annual Conference of the California Weed Science Society in Sacramento. Cudney will discuss the burgeoning problem, research progress and studies to come.

And the news isn't good: Green kyllinga is one of some 600 to 700 weeds in the state, but Cudney said it is one of the toughest he has encountered.

First reported in the state some 50 years ago, green kyllinga has been spreading through the state with unrelenting ferocity. A member of the sedge family, the grasslike plant grows in moist or wet areas that receive full sun, yet also survives some shade and drying once established.

Once a few plants become established, it can spread rapidly. In warm weather, its underground stems can grow more than an inch a day, forming thick mats in just a few weeks.

For home gardeners who tirelessly tend lawns and plantings, prevention is the best medicine. A healthy lawn is the best protection from weeds around the home, said Eddie McCord, a lawn care expert with Green Thumb Nursery in Canoga Park.

``You have to get on a program and make it easy and simple to take care of,'' he said. ``It gets costly when you make mistakes and make them time and time again, which people do.''

Cudney said one theory about its recent spread is that landscapers and home gardeners do not use as many herbicides as in the past. Instead, the concentration is on crabgrass, annual bluegrass and other primary weeds.

``So what happens is you control one weed and something else comes in its place,'' he explained. ``We may have created a niche for it.''

Green kyllinga can be kept in check with repeated applications of herbicide. Two to four applications in two- to three-week intervals will keep the weed from recovering, McCord said.

``It's such a stubborn plant,'' he said.

Preventing new infestations also is critical, Cudney said.

``Thoroughly clean mowers and cultivation equipment before moving from infested to weed-free areas,'' he said. ``If solitary plants of green kyllinga are found, they should be pulled out, roots and all, and the area should be monitored for several months to make sure removal was complete.''

Green kyllinga has been reported extensively in San Diego and as far north as Sacramento, with other spottings in the Bakersfield and Fresno areas, as well as Los Angeles.

Given the ease with which weeds spread, green kyllinga isn't going away soon. Green kyllinga seeds and the weed's root stems are spread by mowing, foot traffic and cultivation.

Weeds love bare ground. Recent golf course renovations at the Woodland Hills Country Club provided prime seeding area for green kyllinga.

``Older courses need rebuilding, so that creates openings for weeds. Somehow, it got there,'' said Jeff Hicks, the golf course assistant superintendent.

After the greens were rebuilt on the No. 2, No. 4 and No. 7 holes, green kyllinga turned up in the rough near the greens.

Then the tee boxes were rebuilt on the No. 4, No. 8, No. 10 and No. 12 holes. Green kyllinga turned up later in the neighboring rough.

Hicks said the club is faced with controlling the established weeds by applying an herbicide after the weed emerges from the ground. They use a powerful herbicide that home gardeners can't purchase over the counter to keep the weed in check.

By using different mowers for different parts of the course, Hicks said, the club also can prevent the spread of seeds and root stems.

``It can be controlled, but you need to get on top of it,'' he said. ``The roots are still there, but as far as visibility, you don't see it, and that's what's important on a golf course.''

Since its texture and color varies from normal grass species, green kyllinga reduces the aesthetic quality of the turf. Green kyllinga also grows faster than most turf grass species, which gives infested turf grass an undulating or irregular surface.

The weed also forms a weak sod that gives poor footing for athletic fields and golf courses.

``If it takes over the turf area, you can't grow grass there,'' said Undem, the Knollwood golf course superintendent.

So Undem, like Hicks, hits hard with herbicide as soon as the weed's long and narrow leaves start showing. ``You want to try and hit it in its life cycle when it's young enough. The leaves are more tender and will absorb herbicide easier.''

Cudney is experimenting with other ways to battle the weed, including reducing watering and different combinations and applications of herbicides.

There are few controls for green kyllinga in ornamental plantings.

Hand removal or spot-spraying of plants will save time and money. Cultivating with a hand hoe can break the root stems into smaller pieces and transplant them into new areas

Also useful can be mulching with landscape fabrics, as long as no light reaches the soil, and herbicide treatments.

YARD BOSS

LAWN CARE COMBATS WICKED WEEDS

A healthy lawn is the best defense against weed problems, and winter in Southern California is a good time to improve the health of your lawn, says Eddie McCord, a lawn care expert with some 40 years in the nursery business.

McCord offers the following tips:

LAWNS THAT ARE DORMANT IN WINTER: Bermuda is the prime variety in the region.

--Core aerate your turf.

--Over-seed with ryegrass and steer manure mulch.

--Don't resume watering or fertilizing until at least March, when warm temperatures generally return.

LAWNS THAT REMAIN GREEN IN WINTER: Tall fescue is the prime variety in the region.

--Core aerate your turf.

--Over-seed bare spots with tall fescue.

--Fertilize in 30- to 45-day intervals year-round, not just in winter.

HELP:

--Seek advice on lawn care from a state-certified nurseryman. Rely on state-certified pest-control advisers and operators for advice on herbicide use.

CAPTION(S):

photo, box

Photo: The characteristic seed head identifies a mature green kyllinga plant.

Jack Kelly Clark/UC Statewide IPM Project

Box: YARD BOSS (see text)