If you are trying to save money, I would nurse this weed patch through the summer and spend your money and time on it in the fall - late August. Now is a poor time to seed new grass because it does not have time to develop sturdy roots before the summer heat hits. Secondarily, if you seed and do the proper watering now, all the crabgrass seed will germinate and take over the lawn by July. If you just start watering proper for a mature lawn now, you'll be surprised how much better it looks. Having said that, if you want a bermuda lawn, then you should start in June or July, so I wasn't thinking of that in the previous paragraph. Set your mower up high. Tall grass and weeds will shade out the lower growing grass and weeds. It also looks more lush when tall. And again, this does not apply if you want bermuda. Proper watering for mature grass is deep and infrequent. Deep means a full inch as measured by empty cat food or tuna cans placed around the yard. Infrequent means once every 2 weeks this time of year and once a week when the temps get into the 90s every day. Mulch mow when you mow. See if you can identify the weeds and plants growing in the lawn so you will know which herbicides will work best when the time comes to renovate. Fertilize with anything, but if you want to improve the health of your soil, use organic fertilizer at least once a year. I use it all the time and life has gotten much better, lawnwise. If I have any lawn issues, I'm confident that poor soil is not the reason. What are the big round green things in the yard?

You're probably not in too bad a shape. It just looks bad because the crabgrass has not died off yet for this year. Crabgrass is an annual plant that must come back from seed. At the first frost it will all die leaving room for your new grass to get going. But who knows when that will be? You just got too early a start on fall. If you used Kentucky bluegrass in the seed, then you can be okay for 2015 with a few tips. If you have only fescue or fescue mixed with rye, then you might want to "dormant seed" again in mid winter. Dormant seeding is when you apply the seed way too early for it to sprout. Then, when Mother Nature gives you a false start to spring with some warmish rains, that seed will germinate without you doing anything. Generally (hopefully) that will happen before the days are long enough for crabgrass to sprout. Kentucky bluegrass spreads to fill in bare spots. Fescue and rye do not. The best prevention for crabgrass is to have a dense lawn that is properly cared for. Different grasses become dense in different ways. KBG will "densify" itself as will St Augustine and bermuda if you care for them properly. With fescue and rye you need to add more seed to get a dense lawn. Best time for that is now. It seems to me the others have talked about a weed killer that will kill crabgrass and leave the other grass alone. You might search this forum for those discussions. Once you have a dense lawn, then proper watering is absolutely critical to preventing weeds. Seeds of all kinds like to have a continuously moist bed to germinate in. If you provide that by watering every day or even every 3 days, you're going to get weeds to sprout. If you have your grass trained to not get water except once a month in the early spring, then unless Mother Nature gives it more often, there will not be many weeds. As the temperatures warm into summer, you will have to water more frequently but never water more often than once a week (except if you live in Las Vegas). Just getting your watering right will eliminate most of the weeds.

There isn't much you can do about the weeds now except preventing them from setting seed -- so I would keep them mowed low as soon as they start their flowering/seed production in late winter/early Spring (this is as soon as we break from the winter pattern and things warm just a little bit -- as early as late February depending on where you are, elevation, etc.). I would wait until late summer/early fall to try to build the lawn (aside from a pre-emergent for summer annual weeds in Spring). The folks over on the lawn forum know a tremendous amount about how to establish a lawn that will choke out weeds. But, I will say that condition number one is you can't grow dense cool-season turfgrass without at least 5-8 hours of sun per day (and the 5 is pushing it). Good luck!

I'm thinking now these may be some kind of round leaf dandelion. Went back over today and took a longer look at them. In less dense areas these leaves have a rosette pattern like dandelion. I just don't recall seeing dandelion leaves with such round leaves before, but I'm not a dandelion expert. Could these purple leaves be dandelions?