Teri Dunn Chace
Teri Dunn Chace is author of more than 35 gardening books, including Landscaping for Dummies and The Anxious Gardener’s Book of Answers. She lives in central New York. TeriChaceWriter.com
When your lawn starts to look worn, patchy or thin, consider overseeding rather than spending extra time and money replacing it.
Overseeding can be used on an existing lawn to thicken up the grass and fill in gaps. But don’t just throw grass seed down on existing lawn and walk away. Take the time to do it right…
Time it wisely. Spring and fall are the best times to overseed. Fall is preferable, because the soil has warmed up and grass will sprout, grow readily and develop strong roots before winter comes. Spring is okay if the ground is not soggy, but summer is too hot and dry.
The right weather and time of day also boosts success. The mild conditions of a cool, overcast morning are ideal for overseeding.
Shop for grass seed. Select a variety or blend known to do well in your area and climate. If you are not sure, ask at a local nursery. Suggestion: Consider perennial ryegrass, which sprouts faster and more thickly than ordinary grasses and blends in well with other strains.
Know the dimensions of the area you aim to improve. Rule of thumb: Two to four pounds of grass seed per 1,000 square feet—about half of what you’d use if you were seeding a new lawn or filling in large bare patches. But these numbers vary by grass types, so consult the chart on the bag.
Set the stage. Seeds must be in close contact with soil to germinate, and existing lawn grass—even thin growth—can get in the way. So prepare the area by mowing the grass especially low, essentially scalping it. Next, run a rake over everything to make the ground as smooth as possible. And if the weather’s been dry, water the area lightly.
Deliver the seed. For a small patch, careful hand-tossing is fine. Otherwise, use a “broadcast spreader”—walk back and forth slowly, first in one direction and then at right angles. Finish up by raking soil lightly over the seeds.
Nurture—and watch! Sufficient water is the key to encouraging grass seed, plus the existing grass will appreciate it. Soak the area immediately after sowing and again a few hours later, using sprinklers or a light spray from the hose. Repeat this twice daily (if there is no rainfall) for about the first week, then just daily for another week or two. By then, little seedlings will be visible. This gentle, consistent irrigation will lead to better and deeper root growth.
Fertilizing is optional—grass will grow fine without extra stimulus. Also we tend to overfertilize our lawns, which can harm or make them dependent on being fed. Excess fertilizer also gets into runoff and can cause algal blooms in ponds and lakes…or even aquatic dead zones.
Once the new grass has reached an inch or two high, nourish the roots by thinly broadcasting a layer of sifted compost.
