Recently, the question of whether or not it is too late to seed has been posed to me by many. The drought that we have experienced during our optimum seeding window has pushed back seeding dates for many. Now the question is do I seed now, do a dormant seed, or wait and seed in the spring. Here are some facts as well as my recommendations that might help you with that decision.
Seeding in October will not result in full-establishment prior to winter, but instead a thin turf stand. This is especially true with Kentucky bluegrass because it germinates and grows more slowly.
Seeding too late in the year can predispose the seedlings to winter injury. Tall fescue and perennial ryegrass seeded late (late October and November) will not be very developed and will be more likely to winterkill, especially in Northern Indiana. Kentucky bluegrass seedlings typically will not suffer any severe winter injury.
Turfgrass seeded at less than optimum times are more susceptible to weed invasion, especially Kentucky bluegrass since it is slow to establish. Unlike a thick established lawn, turf seedlings will not be able to out-compete germinating weeds. Therefore, be prepared to have more weeds than normal next year if your lawn was severely thinned due to drought this year.
Read the herbicide label carefully if the area you want to treat has recently been seeded or you want to seed an area in the future after the herbicide application. Most herbicides require that newly seeded turf be germinated and mown 1-2 times prior to a herbicide application or that herbicides not be applied in the period 3-4 weeks prior to seeding.
Seed now with Kentucky bluegrass, but expect to get little turf to germinate and grow prior to winter. Do not seed tall fescue and perennial ryegrass now.
Seed between December and February as a dormant seeding. The seed will lie there dormant (un-germinated) until warm temperatures return in the spring. This option can be effective for both Kentucky bluegrass and tall fescue. For tall fescue it may be worth waiting until late December to seed to ensure that soil temperatures are cool enough to prevent any germination. This is my current recommendation as of October 15, 2010.
Seed in the spring as early as possible. This option will result a good stand of turf in the spring, but the turf will be weakly rooted heading into summer and will likely have more crabgrass and other summer annuals than other established areas. Additionally, preemergence herbicide applications will have to be skipped in spring seeded area and crabgrass instead will need to be control postemergently after the newly seeded turf has developed.
None of these options are as ideal as seeding in the optimum month of September, but this was not an ideal year for growing turfgrass. Below are three additional links to explore with more information on this topic. The first two links are to two Purdue publications on seedling lawns and the third is a link to a recent post by Dr. Zac Reicher in Nebraska that outlines some data he collected in Indiana on seeding dates.
Aaron Patton, Turfgrass Extension Specialist
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