Mowing at 3-3 ½” will reduce the potential for summer weeds. Photo by Geoff Rinehart
With summer right around the corner and gardening season in full bloom, many homeowners have been spending more time outdoors with yard maintenance activities. One temptation is to “want to do something’’ to make your lawn better since it has been a long, cool spring and it has only been in the last few months or so that things have really started growing. However, it’s important to remember that “doing something” for the sake of just “doing something” can have negative consequences, especially as we enter the hot months of summer.
With spring gardening season right around the corner, lawn questions have been rolling into the Home & Garden Information Center (HGIC). Here I’ll address some of the most common questions about weeds and overseeding.
Dealing with Winter Weeds
Chickweed
In late winter/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 up later in the spring. In my observations, this has not been a particularly bad year for winter annuals. They are favored by wet, mild winters and I think 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, spot spraying with a broadleaf herbicide, or waiting until they die once weather climbs to the 60’s and 70’s on a regular basis. For perennial weeds like dandelion which will start to re-emerge later this month, hand-pulling or spot spraying are the best methods for control.
Warm early October weather has extended the “overseeding window” for fall lawn care. While the first week in October is usually the traditional cutoff for establishing new lawns or rejuvenating existing lawns, the warm early October weather has extended the window by 1-2 weeks.
You can read my September blog post for more information on overseeding and you can still do it, but this follow-up post will deal more with a question that has been coming into the Home & Garden Information Center as of late: “I established a new lawn (or overseeded) in September and some weeds are starting to come up — now what?” Continue reading →
With summer winding down — nights are getting longer and days getting cooler — September is a perfect time to rejuvenate tall fescue lawns. Aerating and overseeding now in the fall will make your lawn stronger and better able to resist pests and weed encroachment for next season.
Here are a few points to remember when aerating and overseeding for a lawn rejuvenation this fall:
The aerator you use makes a difference. A heavier, more powerful (> 5 HP) aerator will be more forceful and more effective in creating deeper cores. Ideally, you should be able to aerify to a soil depth of at least 3-4”. Equipment rental stores often have suitable aerating machines available. Remember not to go over the lawn too fast and allow the machine to just “bump” along. Travelling slowly and ensuring the area isn’t too dry will help encourage quality cores to be pulled from the soil.
Aerifying in fall provides more oxygen to the roots and protected holes for new seed to germinate.
If you have substantial areas of dead grass or crabgrass weeds, it is probably more effective to remove the dead grass leaves with a hard rake, a “power rake”, or a de-thatcher. The turf seed will need to have good soil contact in order to germinate and grow to provide better coverage. By seeding into an area with a lot of dead debris, the seed may germinate and then dry out – or not “take” at all.