Weeds are always with us. Every square foot of garden soil holds thousands of weed seeds, just waiting to sprout any time they get enough sunlight and moisture. More seeds are always arriving on the wind — a single lamb's quarters plant can have half a million tiny, lightweight seeds. And that's not to mention perennial weeds, such as creeping Charlie and Canada thistle, that can live through the winter.
"There's no way to get rid of weeds for good," said Doris Taylor, Plant Clinic manager at The Morton Arboretum in Lisle. "Not even herbicides can keep new weed seeds from landing in your yard. It's always going to be a battle."
There are tactics, however, that will make weeds easier to manage. Here are some tips from Taylor:
Weed early and often. Pull up weeds when they're young, before they can flower and set seeds or grow large enough to compete with your garden plants for water and nutrients. Remove weeds from around your vegetable seedlings as soon as they sprout. The best time to spot and remove perennial weeds such as creeping Charlie is when they first emerge in spring.
Keep weeding. If you set aside a few minutes on a regular basis to pull weeds, you won't face a tangled jungle in August.
Pull weeds when the soil is moist. "After a rain or after you've watered, the roots will slip right out of the soil," Taylor said.
Avoid disturbing the soil. Whenever you dig or till, you expose buried weed seeds to sunlight, enabling them to sprout. Use a type of weeder or hoe that skims below the soil surface, slicing weeds off at the roots, but doesn't turn over lots of soil.
Dig out taproots. Some weeds, such as dandelions and plantains, have a deep, carrot-like taproot. Use a long, slender weeding tool to dig out the whole root so it can't re-sprout.
Don't damage roots. Chopping with a hoe can slice tree and shrub roots. A more surgical approach can protect your investment in the plants you want to keep.
Keep the soil covered. A layer of mulch over your flower and vegetable beds and around the base of trees and shrubs will reduce weeds by preventing sunlight from reaching the seeds. "It doesn't need to be extremely deep," Taylor said. "One inch is plenty to shade the soil in perennial beds. The mulch around trees and shrubs should be an even layer about 3 to 4 inches deep." Weed before you spread the mulch; it won't stop weeds that have already sprouted.
Weed the mulch. The wind will drop seeds on top of the mulch, and if the mulch is moist, they can sprout. Pull seedlings regularly.
Keep weed seeds out of the compost. It's fine to compost stems and leaves of weeds, but not seeds. "Your compost pile won't be able to kill weed seeds," Taylor said. Dispose of them in the landscape waste.