If you are overseeding with a cool season grass it won't germinate until soil temps are above 50 degrees, 55 would be better. Check your soil temps before you do anything.

Please help me understand why acorns are a problem. Are there just too many to deal with?

When does your summer heat start to break? When do the summer night time temps start to cool off. That is the time to seed.

Are the oaks a problem b/c they offer too much shade in the summer and early fall? If you reseed around Labor Day, the lawn should be ready for at least 1 mowing, if not 2, before the leaves drop. If you're worried about the acorns "smothering" the grass - why does it matter if the grass is planted in the spring or fall?

One of the main problems is that the heat doesn't break down here sometimes until November, so I don't have much of a window between when I could overseed, and when I would have to deal with the leaves.

The problem with the acorns is not that they might smother the grass- it is that they start falling in late August/early September, and the squirrels and chipmunks go nuts (pardon the pun). Typically, any seed put down at this time has been largely destroyed by foraging rodentia.

Having never lived under an oak tree - how long do they drop their acorns for? Can you mow/mulch/rake up most of them by mid-Sept? Unless you're re-seeding with KBG, you only need about a 30-45 day window (5-10 days for germination, 20-30 days of growth) until you can just start mulching the leaves (or blowing, but from what I've heard, oak leaves mulch up very nicely).

I do know that some years are "bumper crops" for oak trees - perhaps the "trillion" or so that fell last year were above average?

PS - You may have a potential money-maker on your hands: Yard signs saying "Beware Foraging Rodentia!" - with a silhouette of a squirrel or chipmunk. :-)

On a "good" year, my 75-year old Red Oak can drop as many as 50,000 acorns, and some of these acorns are nearly 1" in diameter. They hurt, and make a hell of a racket on my metal roof! To put it in perspective, this winter I raked up enough acorns to fill a 39-gallon trash can to the rim 4 times--and that only took care of the larger portion in the front yard. I don't even bother with the countless acorns that end up in the flower beds.

Most, if not all of the acorns drop long before the leaves do, which usually don't even begin to turn color until after most other trees such as Maples have already lost their leaves. Point being, overseeding in the Fall has never been successful.

Back to the OT, is it too late to overseed now, given how warm it has been here (65�+ for the last two weeks), even though it is still only February?

What kind of grass do you have? I would think warm season grass would be likely in your area. The type of grass makes a big difference in when to seed.

I have a Fescue lawn, though I have often considered replacing it with a warm season grass, since the summers here are usually quite hot and dry. Not having an irrigation system and a 75-year old Oak tree has made keeping the lawn irrigated properly difficult at best. Not only that, the humid early summer evenings/mornings has more often than not left me with a diseased lawn.

So, I overseed in the spring to try and at least fill in the bare spots that result from drought/disease, but all in all, Fescue has proven to be entirely too expensive, time consuming, and tempermental to care for properly. But what can I do? Replacing the lawn would be just as expensive and time consuming. I'm seriously considering planting clover to take over the entire lawn.

Sounds like you're caught between a rock and a hard place. With the leaves and acorns, fall seeding isn't much of an option, but with the heat, spring seeding doesn't give enough time for the grass to establish to live through the summer.

It's too late for this year, but is dormant seeding an option? I'm not sure if your winters are cold enough, but dormant seeding is my best option. We have heat that lasts through September, then snow starting in October, so fall seeding doesn't work. And the time from snow melt to 90 degree days is also short, so spring seeding fails. Dormant seeding works well for me.

If winters are mild enough, maybe you could even seed late fall/early winter. If the seed sprouts, maybe enough would last through the winter to get a good start. The cold itself doesn't do cool season grasses much harm. What harms them is when the ground freezes and thaws, disrupting the baby roots before they're established. Maybe with your mild winters that would be less of a concern.

That's the problem living in this transition zone. The winters can get cold here--I think we had several weeks of sub-freezing temperatures, yet the summers are often brutal, with 100+ temperatures and sometimes months without rain.

When I bought the house, the lawn was showcase perfect, without a weed in sight. But that's because the homeowner was a professional landscaper who had the skill and means to produce a lawn like that. From what the neighbors tell me, he loved to spend all his free time pampering his lawn. I did the best I could to keep the lawn up, and it looked pretty good for a couple of years, but over time, and several years of intense heat and drought, it is now probably 50/50 weeds and fescue. I think that the region I live in is just too difficult to maintain a cool season lawn. Time to consider some alternatives.