Weeds: An Organic Strategy

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

By Lisa Van Cleef

Learning to live with a few weeds is a gardener's mark of maturity, not unlike that moment when you suddenly stop fretting about the fact that you're too tall or too short and simply decide to get on with life. Weeds compete with your desired, cultivated plants for water, nutrients, sunlight, and growing space. Left alone, they will overrun your garden. If you doubt this, observe an empty lot or untended garden for just one growing season and watch the weeds take over. 
And yet the organic gardener is well served by cultivating a healthy tolerance for some weeds. Complete eradication is unnecessary unless something as insidiously invasive as Canada thistle (Cirsium arvense) or multiflora rose (Rosa multiflora) crops up in your backyard. By tolerating a few weeds, you will make your entire gardening experience more relaxed and enjoyable. And your garden will still be beautiful. There are as many shades of green in this world as there are of gray. 
In the Eye of the Beholder
The concept of "weeds" is a human invention, a way to describe those plants that grow where we don't want them. The mint grown by the last gardener who lived in my house is my idea of a weed. Yours may be volunteer tomato plants from last year's crop that show up in your flowerbed. One strategy for becoming more weed-tolerant is to rework your definition of a weed. A common gauge for weed tolerance is the relative difficulty of getting rid of the plant; perennials with spreading roots, such as quackgrass (Agropyron repens), or deep taproots, such as common pokeweed (Phytolacca americana), are the most persistent, so you will want to keep after them. 
Many plants maligned as weeds, such as milkweeds (Asclepias spp.) and prostrate knotweed (Polygonum aviculare), are highly attractive to beneficial insects that will help pollinate your plants and eat aphids, thrips, and mites. Others are actually delicious edibles. These include dandelion (Taraxacum officinale), common purslane (Portulaca oleracea), miner's lettuce (Montia perfoliata), and common lamb's-quarters (Chenopodium album). (Just be sure you have positively identified an edible weed before adding it to your salad mix.) Some serious invaders such as pampas grass (Cortaderia selloana) and Himalayan blackberry (Rubus procerus) were prized as ornamentals before they bolted beyond the backyard. 
Because their seeds are typically amazingly mobile, weeds can take over quickly. They're spread by birds, the wind, running water, and car tires. Trading plants with friends and neighbors often means trading weed seeds, too. In fact, anytime plants are brought into a new environment, they have the potential of bringing weeds with them. 
An Ounce of Prevention
Even if you do embrace a more casual attitude toward weeds, you'll want to control their growth by focusing on prevention as well as eradication. Weeds are opportunistic plants, popping up wherever conditions allow. With that in mind, think about all the things that you do to stimulate plant growth. Now, to suppress weeds, do the opposite. 
Yank them young
Your first defense against weeds is to pull or hoe them before they get established. Learn to identify weeds as young seedlings and nab them as they emerge. 
Stop the seed
If you don't get them as babies, at least don't let them go to seed. As the old gardening saw goes, "One year's seeding makes seven years' weeding."