How lovely to see a tender green shoot in the garden. April fool! It’s a weed.
“Common perennial weeds are among the first plants to sprout in the spring,” said Sharon Yiesla, plant knowledge specialist in the Plant Clinic of The Morton Arboretum. “One of the ways they outcompete other plants is by having a longer growing season. It’s a bit of a superpower.”
That means one of the earliest tasks for gardeners is weeding. “If you can start dealing with weeds early in the season, it will reduce the number you have to deal with later,” she said.
The plants we call weeds are vigorous, opportunistic species that can grow in often adverse conditions and reproduce freely. If they get a foothold, weeds can compete with trees and crowd out desirable garden plants, robbing them of space, water and nutrients. “You can think of them as garden bullies,” Yiesla said.
Many weeds, such as creeping Charlie (also called ground ivy), dandelions and quack grass, are perennial, meaning their root systems survive throughout the winter to send up those new shoots in spring.
Perennial weeds need to be removed roots and all. “If you only kill or remove the leaves, the roots can resprout,” Yiesla said. When the soil is moist and loose, you may be able to pull the plant up, including the roots, by grasping the leaves and stems. If the roots don’t come up easily, use a weeding tool to extract them from the soil.
“There are many styles of weeding tools available,” said Yiesla. “Try out a few to find one that feels good in your hand and works well in your soil.”
One style, with a slender metal shaft ending in a small forked tongue, is designed to remove dandelions and other weeds that have a long, stiff taproot, similar to a carrot. To use the tool, insert it vertically into the soil next to the taproot until it is 3 or 4 inches deep. Then push the handle to the side to pry the stiff root out of the soil.
Early spring is the best time to tackle weeds that send out long, twining stems among other plants, such as creeping Charlie, bindweed and quack grass. “When they first emerge, they’re compact little plants that are easy to dig up,” she said. “It’s a lot easier than trying to extract all those runners in summer after they’ve snaked through your grass and your perennials.”
As the spring goes on, new weeds will sprout from seeds buried in the soil. Since weed seeds are easily distributed by wind and animals, every square inch of soil inevitably contains hundreds of seeds.
When the plants are new and tiny, Yiesla said, it’s enough to decapitate them with a hoe or cultivator that just skims the soil surface. “You don’t need to drag the tool through the soil,” she said.
In fact, it’s better to avoid disturbing the soil, because every disturbance brings buried weed seeds up into the light where they can germinate. To reduce the number of weeds that sprout, she said, “don’t dig or turn the soil any more than you have to.”
Maintaining a consistent layer of mulch on the soil will also deter weeds by blocking sunlight. Coarse-textured mulch, such as wood chips, is effective around trees and shrubs. Lighter mulches, such as straw and leaves, are useful in vegetable beds, because they will breakdown over the course of a single growing season and add to the organic matter in the soil.
You may still find some weeds in the mulch, most likely growing from seeds deposited on top by the wind. “Keep an eye on your mulch and weed it as diligently as you do your garden,” Yiesla said. “Make weeding a regular practice throughout the growing season, so weeds never get too big or too widespread, and it will be less of a burden.”
For tree and plant advice, contact the Plant Clinic at The Morton Arboretum (630-719-2424, mortonarb.org/plant-clinic, or [email protected]). Beth Botts is a staff writer at the Arboretum.