Although any cool-season grass can be seeded in the spring, spring seedings are more successful with tall fescue and perennial ryegrass than with Kentucky bluegrass. This is because of the faster germination rate and better seedling vigor of perennial ryegrass and tall fescue compared to Kentucky bluegrass. If Kentucky bluegrass is seeded in the spring, consider using a mixture of tall fescue: Kentucky bluegrass (90:10, weight: weight) or a mixture of Kentucky bluegrass:perennial ryegrass (such as 80:20, weight: weight). Seeding Kentucky bluegrass alone in the spring will result in marginal bluegrass establishment in summer due to the slow germination and vigor of the seedlings and increased competition from crabgrass.
Keep in mind that spring seeding and preemergence herbicides don't go habd-in-hand. All preemergence herbicides (except Tupersan) work to prevent the emergence of turfgrass seeds as well as weed seeds, so do not reseed areas treated with a preemergence herbicide this spring or do not apply a preemergence herbicide if you plan on seeding.
For more information about spring seeding, see these previous turf tips.
Aaron Patton, Turfgrass Extension Specialist