After a rainy period weeds come out easily, and there’s no better time than now to get ahead of the problem. The old adage – “One year’s seeds, seven year’s weeds” (English proverb) – quite like Ben Franklin’s “A stitch in time saves nine,” is relevant.
Weeding now will prevent mass reproduction and save you from future back strain and aching hands. If you can remove weeds this week, without walking on wet soil, the timing is perfect.
Garlic mustard (Alliaria petiolata) is a prime example of an invasive plant: one that causes ecosystem disruption and provides no benefits.
(OK, technically it can be used in salads or steamed – but that doesn’t justify keeping it.)
It is listed as an invasive species in many states. Each plant (an annual) produces hundreds of seeds that are easily spread by humans and other animals, and by water or wind.
As weeding goes, this is a pleasant project if you do it before the plant is in full flower, since you can grab several plants at a time and pull them out by the roots.
One sunny morning last week I crawled on my knees, determined to wipe out a new 5- by 7-foot garlic mustard patch in a partly shaded perennial bed.
They were encroaching on some Bear’s Breeches (Acanthus mollis), astilbes, and Eupatorium rugosum ‘Chocolate.’
The garlic mustards were about 8 inches tall, just beginning to show some flowers, and the soil was damp enough that most of the plants pulled out cleanly. If you feel a little breakage when you tug, then use a trowel to dislodge the hidden roots or they will regrow.
Garlic mustard has some special tricks that help it survive and thrive. If you let it lie in a pile, the flowers continue to form seeds that will then disperse. And if plants are left to lie in place some of the roots will reattach in the soil.
For those reasons I filled a wheelbarrow with them and put them in a bag to go into the garbage. While I usually put weeds in a compost pile, these plants could survive composting.
Bedstraw (Galium aparine) is also called Catchweed bedstraw because the plant “catches” on everything it touches, and it was used as bedding or mattress stuffing (bed straw) in ancient times.
It is another annual weed that quickly colonizes disturbed areas and invades gardens rapidly. One plant can produce hundreds or even thousands of seeds, which contain hooked hairs. The seeds and sticky stems cling to clothes and animals.
The plants grow extremely quickly and form dense, spongy mats. It can damage agricultural equipment, decrease crop yields, sicken foraging animals, and the vegetation gets tangled in pet hair. If you have this weed, you will know it.
Controlling bedstraw is possible, but best done early. Hand pulling or hoeing the small plants works, and maintaining a mulch cover is helpful. Mowing is not useful as it effectively boosts the plant growth.
In the last two years I have been amazed by a massive surge of bedstraw in my mixed borders, so I’m out there with a hoe or back on my knees – often and early.
Creeping charlie (Glechoma hederacea) is an evergreen weed that is easily identified by the rounded leaves with scalloped edges and a minty smell. You can pull creeping charlie out by hand, and collect a lot of biomass in a hurry – but do wear gloves since many people get a rash from contact.
If the plants aren’t pulling, then snip off the stems and leaves so you can see the root areas; then dig them up.
Like garlic mustard, these plants can reroot easily if you leave them lying in the soil, so bag them and throw them away. Hoeing or mowing are not advisable, since those techniques spread the plant further. Mulching the area will slow down the reoccurrence of surviving plants.
Cinquefoil is my personal trial – a low growing, ground covering plant with tiny yellow flowers.
It is a species of Potentilla – related to the ornamental Potentilla you may grow in a sunny garden. It grows from long, aggressive shoots that sprout from the crown and root quickly, penetrating mulch, cardboard, plastic and strangling other plants.
You can pull out or dig small patches but any bits of root that remain will regrow. Try a hand weeding tool designed for dandelions to reach below the roots to remove them. Do not mow.
Weed management choices
How to get rid of weeds depends upon what kind of weeds you have – annuals, perennials – and how they spread.
It’s also important to know what kind of crops or plants the weeds are affecting, the bed layout, and how large is the weedy area. Your personal energy and discipline are also factors.
Some of these methods may suit your needs:
• Hoe them: In the examples above, hoeing the plant seedlings in early spring would work only for small bedstraw or garlic mustard plants. Don’t hoe plants that regrow from pieces you leave behind. However, I have often observed that gardeners don’t hoe enough. Many weeds produce tiny seedlings that are easy to hoe – and they are lots more work to pull out one at a time.
• Smother them: If you deny sunshine plants will die. For large weed patches, spread out thick newspaper or cardboard or mulch to discourage or kill them. If they persist and shoot up through those organic mulches, then use heavy black plastic for 6 months to 2 years, depending on the weed.
• Herbicides? As an organic gardener I don’t use them, although some organic products using corn gluten can be effective. If you are considering herbicides you must read and obey the labels – it’s the law.
Preen is a product line that is often misused, as people don’t understand that Preen Weed Preventer prevents seed germination but does not kill existing weeds. (A Preen Weed Control product is available. Read the label.)
Weeding will always be an important part of gardening – so face it sooner rather than later.
Sally Cunningham is a garden writer, lecturer and consultant.