What To Do About All These Weeds?
The famous quotation about the certainties of life that includes death and taxes should also mention weeds. They are sprouting up all over. Even the most meticulously tended landscapes are not immune.
Where to Begin?
The first step is identification. You need to know your opponent. Control is more attainable if you know whether it is a grassy or broadleaf weed. Is it an annual, perennial or biennial? When does it germinate? Fall, spring, or summer?
Begin by browsing through the Home & Garden Information Center weed galleries (https://extension.umd.edu/hgic/topics/weed-identification-photos) forphotos, life-cycle information and control suggestions for a large collection of weeds common in Maryland. If you are still not sure, send a clear digital photo of the entire weed, preferably with flowers or seed heads, through Ask An Expert.
Pick Your Battles
Clover and dandelions are common lawn weeds, but they are not amongst the worst offenders. They provide pollen to pollinators throughout the growing season, particularly in urban areas and early in the season when blooms are scarce.
But, of course, fight back against invasive plants. Invasive species damage the natural environment by displacing more desirable plants that have evolved to provide food and shelter for insects, birds and wildlife. Some invasives, like English ivy and wisteria vines, can kill mature trees. Other invasives such as Japanese barberry have been shown to support higher populations of ticks that can carry human pathogens.
Dealing with Winter Weeds
In early spring, we typically see winter annual weeds in thin, under-fertilized, wet or shady areas. These weeds germinated in the fall and will die as the weather warms later in the spring. This has not been a particularly bad year for winter annuals. They are favored by wet, mild winters, and we had just enough bitter cold in January and a fairly dry stretch through December and January to reduce populations.
Typical winter annual weeds include chickweed, henbit, purple deadnettle and shepherd’s purse. Options to address these winter annual weeds include hand pulling or waiting until they die once weather climbs to the 60s and 70s on a regular basis. For perennial weeds like dandelion that will start to re-emerge later this month, hand-pulling is the best method for control.
Prevention Strategies
Lawns: A healthy, dense turf is your best defense against weed infestations. Something as simple as mowing fescue lawns to a height of three to three and one-half inches will help prevent crabgrass from moving in.
Seeding is most successful in the fall, but overseeding thin or bare areas in the spring to help increase density is an option. Tall fescue grass seed doesn’t need temperatures as warm as crabgrass does, so you may consider trying to overseed in very early April before crabgrass germination gets into full swing.
Gardens: Mulch or plant groundcovers to protect bare soil and when digging or pulling weeds to minimize soil disturbance. When weed seeds are brought to the soil surface, they will germinate.
Vegetable gardens: Spread an organic mulch (two to four inches of grass clippings, finished compost or newspaper covered with straw or shredded leaves) to keep weeds at bay. Or lay a synthetic mulch (black plastic or landscape fabric), cultivate or use a weed trimmer to keep weeds cut back on a regular basis. In the fall, plant a cover crop to keep winter weeds down and improve the soil.
The Last Line of Defense
Herbicides are one tool for weed management that should be used as a last resort and not the first go-to solution. Check to make sure the weed you are controlling is on the herbicide product label, then read and follow the directions.