Is it too late to overseed my lawn? - Ask Extension
I live in Bowie, MD.
I planned to overseed in September and bought seed from Patuxent Nursery in Bowie that is meets your specs for tall fescue typ...
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Is it too late to overseed my lawn? #888995
Asked October 29, 2024, 2:41 PM EDT
I live in Bowie, MD.
I planned to overseed in September and bought seed from Patuxent Nursery in Bowie that is meets your specs for tall fescue type. Health issues precluded this. It's now 10/29.
I wanted to overseed reasonably OK tall fescue (I was going to put down 10% Kentucky bluegrass). I also wanted to till up an area that's overgrown with vines and do a full-on restoration.
Is is too late to do this? I read that seed takes about 14 days to germinate. With straw on top of it, will it survive the first frosts?
Or should I wait until spring (which I know is less ideal).
Thanks,
Sandra
Prince George's County Maryland
Expert Response
Straw might help the seedlings to avoid some frost damage (plus being eaten by birds), as would some floating row cover as an alternative. (We tried this with a late October seeding in some trial beds last year, and it was reasonably helpful in giving the seedlings a slight boost in catch-up growth.) The timing issue aside from temperature exposure, though, is waning daylight. Once we reach the 10-hour daylength of about mid-November, plants (regardless of frost tolerance) generally stop all above-ground growth because they can't photosynthesize enough. Therefore, lawns are running out of time to establish, even if the weather is cooperative or if techniques like the "mulch" above work well.
Establishing sod would be faster than seed, though more costly, and we don't know how available sod would still be this late in the season. Both seed and sod will need regular monitoring for watering needs (another challenge if it does freeze, if it limits hose use) so they don't dry out during germination and establishment.
It's possible that, depending on how successful a seeding is now, that an additional overseeding in spring may still be needed to fill-in any sparse areas. We recommend that overseeding use either pure tall fescue (assuming that's the lawn type you already have) or a blend that includes as little perennial ryegrass and Kentucky bluegrass as possible (as tall fescue is the best-adapted choice among them). If you haven't used it already, the recommended cultivar list may be helpful (see linked page), for this or future seedings.
With the legal cutoff date for fertilizing lawns in Maryland being Nov. 15, there will only be time for one fertilization to give the young grass a boost. It can be repeated in spring. A laboratory soil test, if you haven't had one done in the past 3 years or so, will let you know if it's legal to use a fertilizer formulation containing phosphorus (as seed-starting lawn fertilizers do) for the ongoing maintenance of the lawn. We can help to interpret test results if desired.
Tackling the vine area, if the vining plants have rooted-in to that space (and aren't just covering it with stems while being rooted elsewhere), might not be easy to convert to lawn in one season. Tilling will weaken some perennial vines and may kill annual vines, but won't impact tougher perennial species that can easily regrow from roots or stumps left in the ground. If those were to resprout in a new lawn, it might be hard to treat them since you couldn't dig them out without having lawn damage, and may need to resort to using repeat applications of systemic herbicide. It will really depend on the weed; we can help ID the plants, if needed, with images of foliage and any flowers or berries the vine may have produced. Ideally, competitive weeds should be eliminated before starting a new lawn in a bare area, but there might be workarounds depending on the weed in question.
Miri
Establishing sod would be faster than seed, though more costly, and we don't know how available sod would still be this late in the season. Both seed and sod will need regular monitoring for watering needs (another challenge if it does freeze, if it limits hose use) so they don't dry out during germination and establishment.
It's possible that, depending on how successful a seeding is now, that an additional overseeding in spring may still be needed to fill-in any sparse areas. We recommend that overseeding use either pure tall fescue (assuming that's the lawn type you already have) or a blend that includes as little perennial ryegrass and Kentucky bluegrass as possible (as tall fescue is the best-adapted choice among them). If you haven't used it already, the recommended cultivar list may be helpful (see linked page), for this or future seedings.
With the legal cutoff date for fertilizing lawns in Maryland being Nov. 15, there will only be time for one fertilization to give the young grass a boost. It can be repeated in spring. A laboratory soil test, if you haven't had one done in the past 3 years or so, will let you know if it's legal to use a fertilizer formulation containing phosphorus (as seed-starting lawn fertilizers do) for the ongoing maintenance of the lawn. We can help to interpret test results if desired.
Tackling the vine area, if the vining plants have rooted-in to that space (and aren't just covering it with stems while being rooted elsewhere), might not be easy to convert to lawn in one season. Tilling will weaken some perennial vines and may kill annual vines, but won't impact tougher perennial species that can easily regrow from roots or stumps left in the ground. If those were to resprout in a new lawn, it might be hard to treat them since you couldn't dig them out without having lawn damage, and may need to resort to using repeat applications of systemic herbicide. It will really depend on the weed; we can help ID the plants, if needed, with images of foliage and any flowers or berries the vine may have produced. Ideally, competitive weeds should be eliminated before starting a new lawn in a bare area, but there might be workarounds depending on the weed in question.
Miri
