Work on those weeds one last time
Though it might not seem like it, the end of the gardening season is a great time to think about weed management. Employing a few proactive techniques now can really cut down on the population of weeds in your garden for next season. Here are five action items to take to task this autumn.
1. Uproot and discard as many existing perennial weeds as possible. This includes weeds like dandelions, dock, plantain and sorrel. Perennial weeds are often easier to pull late in the season when the soil is moist from autumn rains and the plants have transferred carbohydrates from their leaves to their roots. Do your best to remove as much of the root system as possible.
2. Do not till gardens where perennial weeds with running roots, such as buttercup, mugwort, Canada thistle and bindweed, are present because each root fragment left behind will generate a new plant come spring. Instead, cut these weeds clear down to the ground, cover the area where they're growing with a layer of cardboard and 3-4 inches of mulch to block sunlight to these tenacious weeds. Leave this barrier in place for a full year to control weeds with running roots such as these.
3. Get rid of winter annual weeds. This group of weeds have seeds that germinate from late summer through the fall. They're very small right now, but the plants continue to grow over the winter and next spring, when they'll quickly flower and set seed with just a few days of warm spring weather. Weeds in this group include chickweed, bittercress, henbit and dead nettle. Even though the plants are very small now, getting rid of them will greatly lessen your weed pressure come spring. Because they're young and tender, a quick sweep with a hoe or a light layer of mulch is often enough to get rid of them.
4. Remove all developing weed seed pods. Any annual or perennial weeds that have finished flowering but have not yet dropped seeds should be “topped.” The process of topping involves carefully removing the developing seed pods to get rid of next year's generation of weeds. Cut down any weed that has yet to shed its seeds and burn the trimmings or throw them out with the garbage.
5. Limit summer annual weeds with a layer of fall mulch. This is an excellent technique for garden areas where weed pressure was extreme this year. Rake or pull out all the now-dead weeds and cover the entire area with a 2-3 inch thick layer of mulch (being careful to keep it several inches away from the base of existing trees, shrubs and perennials). This mulch will serve to bury the seeds of summer annual weeds, such as spurge, carpetweed, black medic, crabgrass and purslane, and the lack of sunlight will inhibit their germination next year. Do not disturb the mulch in the spring or turn the soil in any way. Instead, add another inch of mulch next spring to further suppress weed seed germination.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. Her website is jessicawalliser.com.
Send your gardening or landscaping questions to firstname.lastname@example.org or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.