Weeds are the bullies of the garden. They rob desirable plants of nutrients, sunlight, and water. With a little creativity and diligence, however, you can successfully control weeds in your garden without using pesticides.
The competitive nature
Weeds grow because resources and space are available. The more space occupied by herbs or other desirable plants, the less likely weeds will invade. When I garden, I try to fill nearly all space between plants with organic mulch or black fabric. I look at any bare soil and picture all the weeds that could find a home there over the summer—it’s best to cover up that bare ground. The extra time spent doing this pays off in the energy I save not having to pull weeds. You may also try planting annuals in more narrow rows. This, too, will limit the area that weeds can invade.
Another strategy is to plant a weed’s adversary; planting pumpkins to control bindweed, for example. Pumpkin fights bindweed in two ways. First, it exudes chemicals from its roots that are unfavorable to bindweed. Secondly, its viney growth pattern crowds bindweed and therefore inhibits its growth. While there are no other plants known to chemically inhibit the growth of another, you can strive to plant desirable plants that grow in a fashion similar to the weed you are trying to control. In other words, give those weeds some healthy competition. Also, in areas of the garden that seem to be particularly weedy, any fast-growing plant will help to crowd out the weeds.
Know a weed’s life cycle
Plants have one of three life cycles: annual, biennial, and perennial. Annuals complete their life cycle in one growing season, biennials in two growing seasons, and perennials in two or more years. Understanding your weeds’ life cycles can determine when pulling is helpful and when you’re just wasting your time.
How do you know what life cycle your weeds have? You can tell by the root system. An annual weed has a shallow root system since it starts out new each season. Biennials have a more substantial root system, many times a taproot, similar to that of common mallow (Malva neglecta). Perennials have the most substantial root systems; for example, dandelions have a thick taproot. Many perennials, such as bindweed, have “creeping” root systems that form an underground network, usually many feet deep.
An annual reproduces exclusively by seeds. Therefore, the secret to controlling annuals is to prevent seed production. It is, in fact, more important to prevent seed production for annuals than for other types of plants, because these plants tend to produce vastly greater amounts of seeds.
There’s an old saying that’s still true today: One year’s seeding equals seven years weeding. The seeds of most weeds are characterized by long seed dormancy. In many cases, seeds are still able to germinate even after seven years. For example, 91 percent of jimson weed (Datura stramonium) seeds were still able to germinate after thirty-eight years! So if you pull or cut the weed at or before the flowering stage, you’ll do much to prevent future weeds.
If you haven’t pulled an annual weed and it has produced seed, the best thing to do is bag and dispose of the portion of the weed containing the seeds. This will help cut down on some seed dispersal. It’s pointless, however, to exert much effort in digging up the full weed once it has gone to seed—in fact, the additional soil disturbance from pulling may create a perfect haven for other weed seeds to germinate and grow.
With a root system more extensive than annuals, biennials generally resprout unless the full root is pulled out. They also reproduce by seed. Biennials are usually a bit more difficult to control in gardens because it’s hard to remove the entire root system. Many biennials, however, will not flower until the second year of their life—giving you two years to pull them, in many cases.
Perennials, such as the dandelion, are the peskiest weeds in the garden. After a deep-soaking rain, many people often pull and dig the dandelions and other weeds hoping for a better chance of getting the entire root system. Although moist soil will make pulling the root system easier, even a tiny portion of the root system left behind can resprout, especially in moist soil. So, if you’re going to pull after a rain, put more effort into removing the entire root system.
Other perennials, such as bindweed, have root systems too fine to make complete root extraction possible. The roots of bindweed can extend more than 15 feet below the surface. But digging this deep for bindweed roots will likely do more harm than good since soil disturbance encourages weed seeds and root fragments to germinate. If you decide to pull bindweed or a similar creeping perennial, just pull or cut from the soil surface. To successfully control bindweed with handpulling alone, you’d have to continue pulling every five to seven days after you first see it emerge. Every time you pull this vine, you stress the weed and deplete the underground reserves; enough pulling could eventually starve even deep-rooted perennials.
Weeds are an inevitable part of gardening. I discovered this when I purchased a small home with a rather large backyard. The backyard was essentially a cornucopia of weeds—with a soil seed bank ripe with weed seeds. I spent the first couple of seasons using the weed control strategies mentioned here rather than planting and nurturing my desirable plants, wondering when I would ever get ahead. This past season was my fourth of gardening in my new home, and I can see where my efforts have paid off: weed control is now a peripheral gardening chore rather than the primary focus.