Q. I’ve had a lawn service for the last few years but I have a couple of issues. The water table in our neighborhood is extremely high. I can’t afford to have everything regraded. During decent rains we get puddles in our yard that can take a day or so to go away. One of these is under a maple tree and the result is that the grass is now almost gone. At the very corner, we get an enormous puddle (we call it Lake Hausmann) every time it rains.
This land is lower than the street and is the place the plow pushes the piles of snow. I have reseeded this area every year and each year it turns into a muddy, mucky mess and the grass dies. By the end of July we end up getting crab grass. The backyard is small and extremely shady.
My questions for you are when is the best time to overseed? How do I best do this to get results? Is there anything I can do about the puddling? Is there anything I can do where we get (rid of) Lake Hausmann? I bought a small pump but it couldn’t keep up. In the area by the outtake for the sump pump system, is there anything I can do to get something to grow there? Or should I just put down some mulch?
A. Your biggest overall problem may be trying to grow grass in areas without enough sun or drainage. Grass needs a lot of sun. Maple trees, especially Norway maples, cast dense shade, and that may be the reason grass is dying under that tree. Instead, lay 3 to 5 inches of mulch under the tree, other shady areas, and around the sump pump outtake instead of trying to grow grass there.
Alternatively, you can plant-shade tolerant ground covers such as vinca, pachysandra, or hosta. But before you plant anything, beef up your soil. Cover your entire lawn, or at least all your trouble areas (unless you are going to mulch there), with an inch of compost. This will improve drainage, and also the ability of your grass seed or ground covers to get off to a fast start.
Don’t worry about burying your existing grass. It will grow right up through the compost and be twice as happy. I buy my organic compost and mulch from Mass Natural Fertilizer Co. They deliver by the truckload. Measure how many square feet you want to cover and ask them how much you need.
Once it gets dumped, spread the pile evenly and plant as soon as possible. Rake after scattering grass seed to increase seed-soil contact, and keep it constantly moist with a light hosing until it sprouts. Don’t let it dry out, or the seeds will die. Forget about fertilizing. Good soil is the answer. You and your lawn guy should stay off the new grass for at least six weeks. This is a great time of year to overseed a lawn because spring rains will help keep your planting moist.
As far as Lake Hausmann goes, I would suggest planting flood-tolerant perennial ground covers such as bugleweed (ajuga), astilbe, and/or lily of the valley, which disappear below ground during the winter snowplow season. A thicker lawn maintained at 3 inches in height will shade out crab grass. Lawn companies sometimes mow in the summer when it’s not needed just to keep busy.