Crabgrass will die after frost. To prevent crabgrass next year you can use a pre-emergent when the forsythia bloom (mid March probably). For other weeds wait until next spring and use a broadleaf killer like Weed B Gon. If there are weeds left after that, Weed B Gon CCO will likely take out most (stuff like clover and violets). You planted too much seed. For an overseeding, you should use 4-5 lb of fescue seed per thousand square feet. If you had started with a blank slate (killed everything with Roundup first), the seeding rate is 8-10 lb per K. You used 20 lb per K and it will likely run into problems because it's planted too thiçkly.

+1 Becky. In this case, keep a close eye out for fungal infections, as those become far more likely in a stand that was planted too heavily. If you manage to avoid those, the grasses will thin out over time to where they should be. If you get an infection, it can take out wide sections of the stand if not controlled.

For weeds, as noted, wait until spring. There isn't enough of the season left to bother, and annual weeds will all die when it gets too cold for them. For crabgrass, that's frost. For others, temperatures have to drop below 25. Perennials won't die, but should lose their top growth and cease to bother you over the winter (but they'll be back).

Overseeding again into that mass--already planted too heavily--is a really bad idea.

Hi Chief. You're going to have to decide to stop reading everything and focus on one thing. If you pick this place, I can guarantee success (or dinner is on us). Of course you have to do all the work, but we have a low hassle approach that seems to withstand the tests of time. Even your wife will be able to relax and let the bejeezus settle back into the lawn until next time. Here's the simple deal...

Watering - the mantra for mature turf, like yours will be sometime late next spring, is to water deeply and infrequently. Deeply means 1 full inch all at one time. This deep watering allows the water to penetrate deeper into the soil where all kinds of biological magic happen with the roots and the soil microbes. Infrequent means once per week when the temps are in the 90s, once every 2 weeks with temps in the 80s, once every 3 weeks with temps in the 70s, and once a month with temps cooler than 70s. So what does that mean for between now and June? If you had mature grass it would mean you almost never water until April. Then you water once. If it gets into the 70s, move to once every 3 weeks. You will be gradually increasing the watering frequency as the temps warm. What this does is withhold water at the surface so your grass will develop deep, drought resistant roots. It also withholds surface moisture from the weed seeds which need daily water for a few days to germinate. So simply by proper watering you're doing your grass a favor and fighting weeds at the same time.

Mowing - mulch mow every week at your mower's highest setting or one notch lower. Tall fescue grows much deeper roots which leads to healthier grass all summer. If you need to overseed next fall you can lower the deck for that.

Fertilizer - once in the late spring, once in the early fall, and once in the late fall. If you can remember Memorial Day, Labor Day, and Thanksgiving, you're good to go. DO NOT BE TEMPTED by the TV ads early in the spring to get out there and start spreading fertilizer or weed n feed. If you need an herbicide, it is much better to spot spray individual weeds with Weed-B-Gone rather than spreading stuff all over everywhere. And if you use a fertilizer in the early spring, the grass will be suffering by late spring and you'll be tempted to over apply fertilizer in May. I would make at least one of your annual fertilizer apps an organic fertilizer. Yes, they are real fertilizer. I'm talking about fertilizer and not about peat moss, compost, or manure. Real fertilizer. If you want to know more about organic fertilizer, just ask. I've been all organic since 2002 and many others here can help you. This is not your daddy's organic fertilizer any more.

You should not need to aerate. You read about it all the time in magazines and news papers, and you hear about it from just about everyone, but there's no solid need for it. If you have hard soil after it rains, then we can discuss something else that works much faster and better than aerating.

The crabgrass will die. Other weeds can be attacked with Weed-B-Gone or Weed-B-Gone Chickweed, Clover, and Oxalis killer (stronger solution for special weeds). Again, spot spray the broadleaf weeds. Ignore the crabgrass.

THANK YOU ALL for the very informative responses. I've learned a good bit of information and am definitely thankful.

Chief - if you really want a healthy lawn you should get a soil test from Logan labs. The guys here (morpheus) will read your results if you post them here and will tell you everything you need to do for the next year. It is a great opportunity and for a $25 sample analysis from Logan you can't beat it. You can google Logan Labs in Ohio. When you take a soil sample, don't dig down 4 inches and then sample. Make sure your sample goes from the surface to 4 inches deep (or 6, whichever you prefer).