Weeds: An Organic Strategy

Putting the pinch on pesky plants is partly a matter of perspective.

By Lisa Van Cleef

Organic mulches include compost, shredded leaves, wood chips, bark, dried grass clippings, and other biodegradable material. A 2- to 3-inch layer will keep sunlight from reaching the weed seeds, preventing their germination. Apply mulch immediately after weeding or digging your soil. Take care to keep mulch an inch or two away from plant stems to prevent rot caused by moisture retained in the mulch. Your mulch material will also conserve water, keep roots cool, and nourish the soil as it decomposes. 
Plant densely
Grow plants close together, and they will consume the available space, nutrients, and sunlight, thereby bullying the weeds out of the way. 
Remember not to yank perennial weeds. You'll break off the root, and another weed will appear. Use a long screwdriver or weed-pulling tool with a forked end. Hand-pulling becomes easier as your soil improves. 
Pick your day
Weeding can be an absolute joy after a deep, soaking rain, but don't do it when the soil is soggy. You'll create clumps. And be careful where you walk and kneel: You don't want to compress your soil. Stay on paths and lean into your planting beds instead. 
You may need to use a shovel to dig out persistent perennial weeds. Get as much of the root and runners as you can. It may take several diggings to eliminate something particularly tenacious, such as Canada thistle. 
Use a diamond-shaped or hula hoe to scrape off the top layer of annual weeds. To avoid harming the roots of your cultivated plants, don't dig deeper than 1 inch. Deep hoeing also exposes buried weed seed to sunlight, allowing it to sprout. 
Some gardeners use plastic sheeting, newspaper, and weed-barrier cloth as mulchlike covers. You lay the material over your planting areas and cut holes for your plants to grow through. This blocks out light and smothers young weeds. Other folks (like me) feel that nonorganic mulches are somewhat out of place in the garden. Trying to achieve a weed-free yard is a demanding, unrealistic goal. By simply accepting a few weeds as part of the mix, you will encourage diversity, welcome tasty additions to the salad bowl, and find yourself with more time for valuable gardening experiences, such as afternoon naps in the hammock, something any civilized person can relate to. 
Lisa Van Cleef writes the Green Gardener column for the San Francisco Chronicle's online edition at www.sfgate.com