Hi, thanks for the beautiful pictures. What is that big net in your yard used for? To catch rabbits, right? ;-)

Weed #1 could be bermuda, but I can't say for sure. It could even be Nimblewill or something else. Nimblewill will have thinner stolons than bermuda.

But I'm pretty confident Weed #2 is yellow woodsorrel.

And pretty confident Weed #3 is yellow nutsedge, as opposed to purple nutsedge and the other two or three kinds of sedges.

Yes Weed #7 appears to be crabgrass, but that leaves some of your other weeds still unidentified.

Darn, as I'm writing this at 5:15 AM, the county pickup truck drove by spraying for mosquitoes that could be carrying West Nile virus. The sprayer in the truck's bed makes a high-pitched whine so it's easily heard if you're not asleep. This is the second time I've heard it in the past 2 weeks, I think. I went outside a couple minutes after the spraying. My hands now smell funny--don't know if it's from the spray mist. Time to wash my hands.

Forgot to add: Weed number 4 looks an itty bitty like prostrate knotweed, but I doubt it's knotweed. There are some dissimilarities, especially in the leaves.

I agree the first weed looks like bermuda. That would not surprise me in your area. It is probably fairly weak in the shade and that far north, but during a summer like this one, it would take advantage of any weak spots in the yard. Since you have both bermuda and crabgrass, you must get plenty of sunlight - hard to see on the cloudy day. Still, cloudy day pix are 10x better than sunny day pix, so good for you.

Weeds are normally only a problem in weak turf, mowed too low, with too frequent a watering schedule (or rainfall). Nutgrass is a swamp grass. Is yours growing in an area that gets a lot of standing water or runoff? If not then it is possible you have an underground bucket that tends to hold water longer right there. Perhaps it was scooped out by a rototiller or some other device. Get your soil softened and that should clear up.

Softening should not be done with an aerator. The results will not be what you are looking for. For the past year I have been really happy using clear shampoo at a rate of at least 3 ounces per 1,000 square feet. Spray that down, irrigate a full inch, and repeat in 2 weeks. Your soil should then be soft when you water it or when it rains and gradually become hard again as the days go on when you do not water. At this time of year you should be backed off to watering once every 7-10 days. By the time Thanksgiving rolls around you should be watering monthly. The really infrequent watering usually will take out the nutgrass.

What kind of grass do you want to have? Here are your choices:

Bermuda: takes a lot of work to keep it really nice. Needs heavy feeding monthly, mowing 2x per week, and it turns brown in the winter. It will not grow with any density if it does not get very full sunlight. Spreads fast enough to be considered a pest.

Fescue: much less work to manage than bermuda. Let it grow 3-4 inches high (highest setting or nearly). Fertilize 3x per year with chemical ferts or anytime with organics. Grows from individual plants which do not spread, so if it is thin, or gets thin from drought or insects, it will remain thin until something fills in (weeds usually). Usually it needs to be overseeded every fall. Fescue is the only grass on this list that will grow in the shade. Your shade may be too much for even fescue but you can give it a try. The others will die out.

Kentucky bluegrass: also much less work than bermuda. Feed 3x per year with chemical ferts or any time with organic. Mow at 3 inches. KBG will spread to fill in weak areas. KBG is often used along with fescue just in case the fescue runs into problems. KBG turns brown in the winter although it does not have to if you want to join a band of lawn nuts who have eked out a plan that keeps KBG green all year.

Perennial rye: can be a great lawn but is seldom used east of the Cascade Mountains. Mow high. It does not spread so you will likely have to overseed every fall. Fertilize 3x per year.

If all you want is green, then I would let the current situation go. You might even mix in some Dutch white clover. But if you want one of the regular turf grasses as a monoculture, pick one and we can help you get on track. Now is the time to act. DO NOT WAIT UNTIL SPRING to seed grass.

DCHALL, thank you for all of the information, very helpful! I think you are right on the bermuda assumption. My neighbor has it and we have a driveway seperating us, but somehow its crossed and spread like wild fire.

We did aerate last fall, so that could be the reason of the increased weeds this summer. How do you overseed without aerating?!

So should I try killing all of the bermuda and overseeding? Or do you think I won't have time to seed?

Last year we overseeded with K-31 Tall Fescue, I think I will continue using that until I'm ready to do a full lawn reno and then use a better cultivar. Sounds like I should also mix in some KBG to fill in bare spots too...

I'm always surprised at how well, and how poorly, southern type grasses do on residential properties far removed from the south.
Virginia, a state that can choose to use southern as well as northern cool season grasses and get good results either way, should be carefully examined which, if not both, shows best results. Neighbors who prefer to use one or the other and shows good results can be a guide.

The number of trees and shrubs you have does point out where loss of moisture for the lawn is going. Trees are atypical friends where grass is concerned.
They take, never give, so lawns around the perimeter can be expected to show poor growth.
Even adding a shade-mix to any overseeding may not help.

Increased sunlight--many times just removing lower branches of trees can help. If not lower, than upper reaches of deciduous trees removal of limbs can open the canopy to more sunlight.

Have you ever given thought to using a combination lawn seeding program that uses cool season grasses; Kentucky Blue 40%, 30% perennial ryegrass and 30% fescue. I'm not aware that Bermuda can be mixed in.

Adding organic material to the lawn can improve its moisture holding capacity and build soil structure.
Overseeding in the fall, when there is no competition from weeds, is always a good rule to follow.
Aerating a lawn once per year as you have done can help it retain moisture and spread fertilizer benefit th0rough the soil.