Landschoot suggests avoiding annual ryegrass, also known as Italian ryegrass, which is one of the most commonly sold grass seeds. It’s also found in some professional landscaping mixes. “Annual ryegrass may establish a few days before other ryegrass,” he says, “but most people don’t like its coarse texture. It thins out quickly so that after a few years, you’re back to ground zero.”
Another good choice for a sunny lawn is tall fescue, a drought-tolerant, low-maintenance species. “Buy a good quality, ‘turf type’ tall fescue from a reputable dealer,” he says. “Stay away from the variety Kentucky 31. Most people are dissatisfied with its large, coarse clumps.
Till and rake the soil as if starting a new lawn. “The grass needs time to establish before the trees leaf up and make shade next summer,” he says.
Sun (with some shade). For a sunny lawn with some trees, Landschoot suggests a mix of 40 to 60 percent Kentucky bluegrass, 30 to 40 percent fine fescues and 10 to 20 percent perennial ryegrass. “The Kentucky bluegrass and ryegrass will predominate in the sunny areas and the fine fescues do well in the shade,” he says.
Perennial ryegrass for dead patches
To calculate the amount of Kentucky bluegrass seed you will need:
C: Divide the recommended seeding rate by the PLS weight (1.5 / 1.04) = 1.44 lbs.
D: Multiply C by pounds per 1000 sf (1.44 x 1.5) = 2.16 lbs.
Seed mixtures are normally sold by weight of each component that makes up the mixture. Occasionally, specifications are based on the actual pure live seed (PLS) seeding rate or each kind or variety in the mix. Seed mixed and labeled as Maryland Interagency Certified mixtures (blue tag) or as meeting the specifications of the Maryland State Highway Administration (orange tag) must meet high standards of purity and germination.
A: Multiply the % pure seed by the % germination (0.9867 x 0.70) = 69.00% PLS
B: Multiply the % PLS by the required weight (0.69 x 1.5) = 1.04 pounds
A: Multiply the % pure seed by the % germination (0.9908 x 0.95) = 94.13% PLS
B: Multiply the % PLS by the required weight (0.9413 x 6.0) = 5.65 pounds
The 6.0 pounds of perennial ryegrass contains 5.65 pounds of viable seed (PLS). Thus, to apply the recommended seeding rate of 6.0 pounds per 1000 sf you will need more than 6.0 pounds of this seed.
The 1.5 lbs. of Kentucky bluegrass only contains 1.04 pounds of viable seed (PLS). Thus, to apply the recommended seeding rate of 1.5 pounds per 1000 sf you will need more than 1.5 pounds of seed:
For example: a specification requires that 6.0 pounds of perennial ryegrass and 1.5 lbs. of Kentucky bluegrass be applied per 1000 sf. This would appear to be an 80% / 20% mixture applied at 7.5 lbs./1000 sf.