How to Seed a Lawn
Prep your lawn for next spring by getting grass seed down at the right time of year
If you've spent the summer lamenting your tattered yard or wishing that your patch of dirt were a blanket of soft blades, you can stop. It won't get any better, at least not this year. But next spring could be a whole other story if you seed this fall - the perfect time to start a new lawn. In cold-weather climates, fall's cooler temperatures prevent the seeds from drying out, but there's still enough sun and rain to help them germinate before going into hibernation for the winter, without the competition of crabgrass and other weeds that die off this time of year. And the best part is that the whole process is a cinch. “Seeding is the easiest thing for a homeowner to do,” says This Old House landscape contractor Roger Cook. “It just takes a little soil preparation, the right mix of seed, and lots of watering."
As with most landscaping projects, preparation is the most critical part of seeding a lawn. The condition of the soil has to be ideal to coax the tiny grass seeds into germinating. That means using well-turned earth with proper drainage and the right chemistry.
To get these conditions, you first need to remove any vestiges of the old lawn. Renting a sod cutter for about $75 to $100 a day allows you to slice off old grass and weeds at the roots. Then it's time to turn the soil with a rotary tiller, adding sand and compost in successive layers to achieve an ideal mix.
But even with these additions, no soil is ready for seeds if it doesn't have the right pH. The pH scale measures acidity and alkalinity, denoted by numbers from 0 to 14, with 7.0 being neutral. Grass grows best in soil that has a pH between 6.0 and 7.5. If your soil is too acidic (below 6.0)—a common problem in cooler wet climates like the Northwest and Northeast—you can add lime to bring it up. If it's mildly alkaline (7.5 to 8.0), a little peat moss, which is naturally acidic, should correct it. Soil that is very alkaline (more than 8.0), which is more likely to exist in dry, hot climates, needs sulfur.
All soil could use a little fertilizer boost to nourish the seeds. Then once the soil is ready, the actual planting is cake. Just throw out the right amount of seeds, gently rake them into the turned earth, and make sure they get enough water to keep on growing.