Controlling Annual Weeds, from www.yardener.com

Minimize Soil Disturbance - There are a number of effective techniques for reducing annual weeds in the flower bed. These techniques either break the reproductive cycle of the weeds already on your property, or they keep new weeds from getting into the area in the first place. The best way to control annual weeds is to prevent them from emerging. That means minimizing the disturbance of the soil and then mulching the garden beds very well. You minimize disturbing the soil because there are 20,000 to 30,000 weed seeds under every square foot of your garden bed just waiting to be exposed to light so they can germinate. Every time you dig a hole to plant another perennial, you are exposing hundreds and thousands of weed seeds to likely germination if nothing is done. We assume that the first time you establish the bed or garden you must dig it up and perhaps even rototill the area to get the soil prepared. After that you should have the whole bed covered with 3 to 4 inches of organic mulch all year round. From then on you disturb only that portion of the bed where you are adding a plant, planting some seeds or bulbs, or transplanting a plant.

Mulch to Control Annual Weeds - The absolute best way to solve an annual weed problem and prevent it from ever coming back is to use a layer of organic mulch during the entire year. Mulch does a number of good things for the flower garden, and weed control is one of them. A 3 to 4 inch layer of wood chips, pine needles, chopped leaves, or shredded bark mulch over the surface of the growing bed prevents almost all annual weeds from getting a chance to even germinate. Those few weeds that pop up through the mulch where landscape plants protrude are easily pulled by hand.

Pulling Annual Weeds - Routinely pull a few weeds each visit to the garden beds and the weed pulling never becomes an overwhelming task. Try to get rid the garden of annual weeds within the first 3 weeks of their emergence, before they have a chance to develop seeds. Weeds are easiest to uproot right after a rain, when the soil is damp. It is important to pull up the roots, rather than just breaking off the stem. Grasp them between the thumb and forefinger down at the base of the weed at the soil. Pull slowly and steadily, rather than jerking the weed abruptly out of the soil. As the season progresses, the number weeds appearing should diminish.In fact, pulling up all the annual weeds that appear in a season will result in only about half as many weeds the next year, and half again the third year, assuming the bed stays mulched all year long. In two to three years you will have almost none. The key is keeping the mulch at least 2 inches thick all year.