Bermuda is a warm-season grass that loves sun, but doesn't do so well in shade as you've probably already figured out. In the right conditions, it can grow quickly and be invasive. It goes dormant (yellows) in the winter and during extreme drought. If you want more Bermuda grass, now is the time to plant seed.

Zoysia is another warm-season grass that is supposedly more shade tolerant. How shade tolerant, I'm not really sure. It is slow growing, and probably a little easier to weed out of flower beds. It also goes dormant in the winter and during extreme drought. Sod is the best way of starting it, but it is more expensive than other common grasses. You can also sprig it, and there are a couple of seeded varieties, but it will take a year or more to fill in. Again, now is the time to plant it.

There is also Buffalo grass, but I don't have any experience with it. From what I read it does best out in western Oklahoma and in poor soil.

Then you have your cool-season grasses like Fescue and Kentucky Bluegrass. From my experience, Tall Fescue is about the only thing you can grow in the shade in Oklahoma. It is a clumping grass that doesn't really spread on its own other than the clumps getting bigger. You will need to keep it watered during the hotter months if you want it to survive. Even then, patches of it will die out, and you'll have to overseed in the fall. It stays green year-round if you can keep it watered. I have never had much luck with the big brands such as Pennington, Scott's, etc. that you find at the big home improvement and discount stores. There are varieties that are more drought tolerant and better suited for growing in Oklahoma sold at regional chains such as Westlake or a local nursery.

That is just my experience, so your mileage may vary.

We've been having the same problem with our grass as well. My husband went to a local grass seed store that helped us out. They suggested that we plant a mixture of perenial ryegrass and a turf blend fescue (that's not suppose to clump as much as standard fescue). So far it looks awesome!!! The ryegrass will sprout in only a few days, while the fescue will sprout in a week or more. It needs quite a bit more water than bermuda does, so we'll see how it looks after the heat of the summer. Also, the ryegrass will live through the winter so it will need to be mowed. If you are like us though, any sort of grass is better than mud. We also have a 90 lbs bloodhound that regularly "tills" the yard up with his huge paws, and the new grass doesn't seem to be too affected by it. So I would say that it is definitely hardy. The ryegrass is also suppose to be good for sunny areas of the yard as well. We have only planted it in the shade though, because that was our problem area. Someone told us that you can only plant it in the Fall, but another person told us you are only suppose to plant it in the Spring. We planted our about a 2 months ago and it has done very well. We actually reseeded a week ago too, just to fill in a couple of spots. It seems to be doing well and is already filling in the holes. Our plan is to do more reseeding in the Fall as well. So, the spring worked for us. It may be a little too late to plant right now, but a 50lbs bag was only $40 so it is worth a try. WAY less expensive than resodding.

Here is a before picture and an after picture of what it looks like. The before picture actually has tiny neon green sprouts, but you can tell how spotty and clumpy it originally was.

This is just our experience. We are new to the whole grass thing.

By the way, it's the softest grass I've ever felt in between my toes! It makes you want to lay on it and roll around... Well, at least it has that affect on me :)