Whether you are growing ornamental grasses or seeding a lawn, understanding how grasses germinate and grow is key to the health of the plants. Although each grass species is different, they also have common traits.
Northern climates are cooler and have shorter growing seasons. Grasses suited to cooler climates include Kentucky bluegrass, ryegrass, some types of fescue, and bentgrass. Warm-season grasses are better for most Southern climates. Varieties suitable for these areas include Bermuda grass, zoysia grass, St. Augustine grass, Bahia grass and centipede grass. Some warm-climate grasses grow well in colder climates and some transition areas can support grasses from both lists.
Germination temperatures will vary for different types of grasses, but as a general rule the soil must be warm enough at night to promote quick germination. Planting grass seed too early, when nighttime soil temperatures are still too cool, may result in poor germination. The soil temperature should be above 65 degrees.
Placing a very thin layer of mulch over the grass seed can prevent birds, insects and animals from eating the seed. A thin layer of mulch also will help keep the seeds moist, resulting in a higher germination rate. If the mulch is too thick, the grass will have difficulty reaching sunlight after germination.
Freshly seeded grass should be watered twice a day until germination. If the seeds are allowed to dry out, even for a day, germination rates can fall. After several days without water in very dry climates, the majority of seeds may not germinate.
Some birds are very fond of grass seed. In addition to applying a thin layer of mulch to deter them, try hanging old or unused CDs from tree branches. The reflections from the CDs often startle birds and make them think a predator is approaching. If you don't have trees, hang CDs from wooden posts driven into the ground. Some garden supply stores also sell reflective ribbon that you can run across your lawn to keep birds off of the seed.