I think it's a mistake to mix Bermuda and tall fescue. Tall fescue is a cool season grass and Bermuda is a warm season grass. What you'll end up with is a lawn that has splotches of green fescue mixed with brown bermuda in the winter and green bermuda mixed with brown fescue in the heat of summer.

Also, Bermuda thrives when it is fertilized with 1 lb of N per 1000 sq ft per month during its growing season and it does best if it's mowed really short (like an inch or less) and may need to be mowed several times a week.

Fescue only needs about 3 lbs of N per 1000 sq ft per year and most of that would be best applied while Bermuda is brown. And it should be mowed tall.

You're growing two different grasses with very different requirements so it's tough to tell you what to do and when to do it.

Yeah, I was just reading online how to fill in all the holes that were inbetween fescue (since I couldn't seed more fescue in hot weather). I probably won't be adding anymore bermuda, just stick with the tall fescue. Which is wierd, if it's a cold season grass, then how does it grow so good in this zone 9 110 heat? Shouldn't it be the opposite? I noticed it goes somewhat dormant, and doesn't grow hardly at all for about a month when it's over 100...but it stays nice and green! I mow at about 2.5" and the bermuda doesn't seem to mind. The bermuda grows good too, but I like the way fescue looks better...and it's about half the price. I'll probably stick with fescue since it'll be green in winter too.

So what schedule should I use if I'm going to stick with my fescue mix? Should I aerate, seed, or fertilize first?

The new seeds can't use any fertilizer until they start growing, so fertilizing before the new seeds are growing will just cause the existing grass to grow faster and make it tough to wait on mowing until the new grass is up. I'd mow as short as possible, core aerate to expose more soil, then seed.

Okay, so I'll mow short, then aerate, then seed with tall fescue mix all in the same day. Should I do it now (while it's in the high 80's during the day, 50's overnight), or wait until it gets a little cooler? How close do you aerate, like how many holes per square foot? I just have a little 2-hole handheld aerator (my lawn isn't that big so it won't take too long).

Then I would fertilize maybe 2 weeks after aerating/seeding? How long should I wait then?

If you can water enough to keep the seeds moist you can water now. If not, you can wait. Fescue germinates pretty quickly so you only need a month or so before a freeze.

As many holes as possible.

Fertilize when the new grass starts coming in.

Very cool, is it okay to seed right after aerating, or would that not be good because of the 4" deep aerator holes? Should I seed first, then aerate in the same day? Last question about this, almost got it narrowed down! Thanks for all the help.

Got it, I'll be fertilizing a few weeks after I do the seeding/aerating.

Aerate first, then seed. You can seed as soon as you're done aerating.