How to Get Rid of the Toughest of Weeds
Weeds have developed traits that make then top-notch survivors, allowing them to colonize and choke out weaker competitors. Learn how to beat the worst weeds.
Good Timing: Winning the Battle Against Weeds
Good timing is key in marriage proposals, stand-up comedy, and parachute opening, but it’s also very helpful in winning the battle to control weeds in the yard.
Employing the right strategy at the right time can make the difference between success and frustration.
Since weeds come in many forms with differing life cycles, differing growth habits, and differing vulnerabilities, no one-size-fits-all strategy solves all problems.
Some weeds come up every year from new seeds, so they can be stopped before they get started. Some of these weeds sprout in fall and survive the winter, then have a growth surge as soon as the weather begins to warm in spring. Dropping new seeds by the time summer arrives.
Other annual weeds sprout and take root in the warmer temps of spring or early summer and grow all summer before dying in fall, so different timing is needed to keep a lid on those.
And many others come back year after year from their own roots, so they have to be dug, sprayed, or smothered.
Deciding which control option to use, and when to use it when depends on which weeds you have. That’s why it pays to “identify the enemy” – or at least know what type of weed you have.
Be sure to get whole plants – roots and all – when digging weeds. George Weigel
The yanking option
Digging and/or pulling a weed is the option that’s least reliant on timing. Any weed can be yanked most any time to eliminate it, so long as you remove the entire plant, ideally before it produces seed.
Be aware, though, some plants can come back with a vengeance if you leave even a small piece of root, rhizome or a bulblet behind. Thistle, dandelions, Japanese knotweed, goutweed, wild violet, and yellow nutsedge are prime examples. The solution is to use a digging tool to loosen and remove all underground parts instead of just ripping off the above-ground foliage.
The other caveat relates to weather. It’s much harder to remove complete weeds when the ground is frozen, and although weeds generally come out easier in wet ground, you’ll do compaction damage to soil structure by walking on it when the ground is wet.
This purple dead nettle – a winter annual weed – is in full flower and soon ready to spew seeds for next year’s plants. George Weigel
Preventing trouble
Annual weeds – ones that die at the end of each season and sprout anew the next year – are vulnerable to control before they ever get started.
First, be sure to keep weeds from going to seed, which eliminates that seed supply for next year’s weed crop. Then you’re down to controlling only the weed seeds that come into the yard from elsewhere.
Read about the many ways weeds can get into your yard
A two- to four-inch layer of mulch over bare ground discourages the sprouting of new weeds in garden and landscape beds.
Granular weed preventers such as Preen create a barrier over beds that stops weed seeds from germinating into young plants.
Preen is easy to apply over soil or mulch to create a barrier that prevents new weeds.
Preen can be used over top of most existing landscape plants since the active ingredients are weed preventers, not weed or plant killers. (See the label for exceptions.)
Timing comes into play depending on the type of weeds.
Some annual weeds are so-called “winter annuals” that germinate in the cool soil of fall and early winter, then grow and flower early the following year. After dropping their mature seeds, they die.
Examples are common chickweed, hairy bittercress, henbit, purple deadnettle, speedwell, and annual bluegrass.
Other annual weeds are “summer annuals” that germinate in later spring or summer, then grow, flower, and set seed in summer or early fall. That seed lies dormant until warm weather the following year.
Common summer annuals include foxtail, purslane, pigweed, lambsquarters, spotted spurge, black medic, groundsel, and yellow woodsorrel.
An application of Preen Extended Control Weed Preventer in early spring is effective at preventing more than 100 kinds of weeds for up to six months.
A second application in late summer to early fall gives protection against winter annuals for another six months. The two together add up to season-long protection.
Perennial weeds need to be eradicated, either by mechanical removal or spraying at prime time. George Weigel
Existing weeds
Perennial weeds are the durable ones that come back year after year from their own roots.
Examples are dandelions, plantain, chicory, curly dock, hawkweed, mugwort, wild strawberry, Canada thistle, birdsfoot trefoil, and bindweed.
Although weed preventers can prevent some new perennials from germinating, they don’t work against weeds that are up and growing. Perennial weeds need to be killed or removed.
Besides digging, they can be killed with a variety of herbicides. Some herbicides come in granular form that are aimed primarily at lawn weeds or large patches of weeds. Others come in spray form that can be targeted to individual plants.
Although most herbicides are at least somewhat effective any time perennial weeds are actively growing, they work best when daytime temperatures range between 55 and 85 degrees.
They’re also particularly effective in early fall when perennial weeds are preparing for winter by sending plant carbohydrates from the leaves to the roots. Herbicides also move best then to the roots.
Different herbicides work better against some weeds than others, so read the labels both for ideal timing and to make sure the product you’re using is labeled to control the weeds you have.
