It's War On Weeds

But when a mother lode of seed from these fast-breeding, water-hungry plants germinates in a garden, particularly a drought-tolerant garden in Southern California, it's war. It's a water war.

By weeding after winter rains, you can allocate water to the right plants and cut off the thirsty interlopers. You'll snare the seeds of weeds before they can spread. You'll also clear out a sweaty little under-zone of greedy greens that block air and light from the plants that you want to thrive.

The benefits are clear. The question is how best to achieve them. You are never more of a gardener than when you weed. You are physician, botanist, architect and explorer.

Though it sounds incongruous and wasteful, experienced gardeners often water a couple of times in advance of winter rains in order to force weeds up. Pull this crop, and you reduce the spring surge. The process is essential for wildflower gardens if the poppies are to survive early competition from crab grass.

As effective as this strategy may be at reducing the early winter weed load, seeds still blow around and are tracked by cats, birds, dogs and us. Weeds don't germinate on cue, either. Part of what makes them so formidably successful are complex triggers calling for successive rounds of sprouting. Dandelions are the first to react to lengthening days. Rye grass responds to water.

Weeds can be grasses, vines, shrubs or tree seedlings. The one thing weeds have in common is that they all love disrupted soil. Del Tredici says they especially love disrupted soil that is irrigated and fertilized.

In other words, weeds love our gardens.

The best way to control the explosion of weeds in a good rain year is to get them while the soil is moist and the temperature is mild. A battery of tools and techniques bespeak a gamut of philosophies about how to do this. Mow them down. Rake them out. Yank. Dig up each one with a fork. Poison them.

Which to use? The answer lies in situation, size and ethics.

For weeds in lawns, most homeowners just mow, though every spring certain companies spend a lot of money exhorting Americans to treat yards with "weed and feed" products targeting dandelions, clover or anything else that might attract a bee. The herbicide in this mix is usually 2,4-D, or dichlorophenoxyacetic acid, which works by overwhelming the weed's hormone system. In dandelions, it essentially causes the plant to grow itself to death.

Arizona State University environmental chemist Thomas M. Cahill once explained this process as "cancer for plants." Among critics of the approach, discussion continues as to whether it causes cancer in people.

For crab grass under fruit trees or in hedges, rakes and hoes are the answer. Rake back the mulch, then use a hard-tonged rake or hoe to take out the weeds. Once that's done, smooth over disturbed soil and restore the mulch. Even water it lightly to stop the soil from drying out.

UC Davis weed guru Joseph DiTomaso is a fan of the hula hoe, also known as the stirrup hoe. It can clear a weed-clogged fence border fast. Under fruit trees, I use a hard-tonged bow rake. It pulls plants with minimal soil disturbance.

In flower beds, particularly wildflower beds, pulling weeds by hand is best. Do this immediately after a rain and in the early morning or late afternoon, when the soil is moist and any disruption of the crust can be quickly and neatly patted down to protect roots of neighboring seedlings. When pulling, grasp as close to the root crown as you can get, then feel for the angle of least resistance and tug. The less soil you unearth while weeding, the more skillful you are becoming.

If the roots run deep, or if you're dealing with dandelions' tap roots, then a garden fork is helpful. Better yet, DiTomaso says, are long slender tools such as the asparagus fork (also called a weeding knife) now in fashionable garden tool supply catalogs. Slip the fork down the root line, wiggle slightly and tug.

Not sold? Anything long, strong, sharp and slender should do the job. If rye grass rises between pavers, try an old screwdriver, slowly moving it along the soil and flipping out the weeds.