By Sean James

Though many homeowners have been trained to apply fertilizer several times a year, two far more important lawn regimens—which render fertilizing all but unnecessary—are top-dressing and over-seeding.

It is important to know the difference between seed types and their specific benefits and drawbacks. Most North American lawns are predominantly Kentucky bluegrass, which, in essence, is an insect and disease buffet, which isn’t tolerant of either prolonged drought or shade. If you have a sunny lawn, a mix of perennial ryegrass and tall fescue, at triple the rate recommended on the bag, is best. Perennial ryegrass actually repels chinch bugs and is quite drought tolerant, while tall fescue has extremely deep roots and will withstand the worst drought. New varieties of each are hardier and more finely textured, ensuring a beautiful lawn. If you have a shady lawn, opt for chewings fescue.

After spreading the seed, apply 13 to 25 mm (0.5 to 1 in.) of compost over the entire lawn. Covering the grass seed helps it germinate and organic matter will help keep the seed moist until that process begins. If you’ve never done this before, do it once a year for the first two to three years; then, you can cut back the schedule to every other year.
If your lawn gets a lot of foot traffic, it would be beneficial to perform a spring aeration before over-seeding and top-dressing. Aeration involves punching holes into the soil and is performed using a machine that looks like a souped-up lawn mower. It should be done when soils are slightly moist to ensure the best penetration. The removed bits of soil, referred to as cores, should be left on the grass, where Mother Nature will break them down and use the soil to biodegrade excess thatch. (Thatch is a layer of dead grass leaves on top of the soil and is generally only a problem if you’re over-watering and/or over-fertilizing.)

This article is part 6 of 8 from our blog series “Keeping it Green: Beautiful turf can be sustainable, too“.