The Best Time to Plant Grass Seed in Maryland

If you make your home in Maryland, growing a lawn from seed is the most common way for you to have a nice yard full of beautiful turf. Maryland's climate can be challenging for growing and maintaining grass year-round, though, because the state is located in a transition zone — an area where different climates meet.

Maryland has both subtropical and temperate climates. So before choosing a grass seed to plant, it's important to know whether your climate zone is best suited for a cool-season grass or a warm-season grass.

Sowing grass seeds in the late summer or early fall is important to ensure that the seeds germinate before the first frost arrives. Seeds typically take around two weeks to germinate. Mid-August through mid-October is a good time for planting grass seed because the climate isn't too hot or too cold, so the seed has ideal conditions to get a head start. It's also possible to sow seeds in early March and April when weather conditions are favorable.

The best time to aerate a lawn in Maryland depends on the type of grass you've planted. Aerating is the process of using a piece of equipment called a core aerator to remove small plugs of soil so the lawn's roots have easy access to air, sun, water, and nutrients. Aeration is important to reduce compaction of the soil.

If you have a cool-season grass variety, you'll want to aerate in the fall, whereas the months of June and July are ideal if you have a warm-season grass. You should plan to aerate when the grass is thriving. Avoid aerating when the grass is dormant to reduce the risk of harming the lawn. Before you aerate, check the moisture level of the soil. If you find that the soil is dry, you'll need to water your lawn in advance.

The best time to overseed, or plant new grass seed over bare patches of lawn, depends on where you live in Maryland, as the climates vary and influence growing conditions. Typically, late summer or fall — about a month and a half before the first frost hits — is a good time to overseed because daytime temperatures are moderate and nighttime temperatures are cool. Spring can be an alternative time to overseed since conditions are also good, and rainfall will help to keep the soil moist to support germination.