Grapes grow very well here. The only problem we have had is keeping the birds from eating them all. I find the yard fills with mocking birds as soon as the grapes appear. The mocking birds chase the squirrels away, eat the grapes, then leave only to return next year.
Grapes must be heavily pruned to fruit. Prune as soon as new leaves appear. Prune heavily, cutting back to the strongest branches on each plant. Train grapes along posts and strings. This allows air and light to get to all of the vine.
Grapes like most fruit plants want full sun. These are doing fine and receive sun all afternoon, but no morning sun.
Fertilizer is not recommended or needed for grapes. I put some worm castings down in the spring. I’m told fertilizers ruin the taste of the grapes so stay away from them.
Grapes want lots of water while getting established and should be fine after that. Grape roots will go as deep as 30′.
Houston temperatures are fine for grapes, both the heat and the cold. They will drop their leaves in winter and are one of the last plants to put out new leaves each spring.
I gave up on the grapes, the mockingbirds ate every crop