First things first, gently rake leaves, twigs, and dead grass off your lawn, and remove snow mold if you live in colder climates. This allows air and sunlight to reach down to the grass roots. Avoid power-raking, as hacking away at the ground can damage shallow grasses and good soil.
Weeds like dandelions, hairy bittercress, common chickweed, and henbit go dormant in winter and re-emerge in the spring. For best results, pull as many weeds as possible by hand or use a hoe. Be sure to get the entire plant, roots and all. If you use a pre-emergent weed killer, make sure it’s a calm day. Wind can spread the chemicals onto plants you don’t want to kill and into waterways you don’t want to pollute.
Aerating — making small holes in your soil — lets air, water and nutrients reach the roots of your lawn, encouraging healthy growth. On newer lawns (1-3 years old), aeration is encouraged twice a year, in the spring and fall. After that, you can switch to once a year in the spring. Don’t rake the plugs; leave them on the lawn as topsoil. Mow over them, and they will decompose naturally.
Overseeding is the practice of spreading grass seed over your existing lawn. Cover bare and thinning patches of grass using a mix of seed that includes slow-growing and low-growing grasses — fine fescue or centipede grass, for example. Cool-season grasses such as bluegrass and annual ryegrass benefit the most from overseeding.
Watering early in the morning prevents wasteful water evaporation and lets the grass blades dry before evening, which helps prevent insect and disease issues. Watering deeply and less frequently makes the roots stronger and deeper. Soil should be moistened to a depth of 6 inches a couple of times a week. Avoid overwatering, as soggy roots will rot and attract disease and insects. As a test, take an 8-inch screwdriver and push it into the lawn. If it goes in easily, your lawn is moist enough.
Fertilizer helps keep your lawn healthy, so it can resist disease and weeds. Grass often needs more nitrogen, phosphorus, and potassium than the soil naturally provides. Use fertilizer before the heat of summer but avoid fertilizing when the ground is wet, or you risk fertilizer burn.
When the grass is growing well, it’s time to mow. The proper mowing height will depend on your type of grass, but for good lawn health, follow the “one-third” rule: Never cut off more than one-third of the length of the grass. Mow more often when growth is peaking and back off when grass growth slows. It’s also best to “grasscycle” by leaving the grass clippings on the lawn. They return moisture and nutrients to the soil, so you’ll need less fertilizer.