Have any pictures? Brazos is usually an easy blackberry to grow.

my own experiences with blackberries and raspberries would lead me to believe that they take awhile to settle in. once they have their root systems growing, they're very tough and even a nuisance.

it's a hot time of the year to plant them.

i suggest some shade cloth (cheaply got from lowes, pin it down on the plants), lots of water (daily and heavily) and deep mulch. don't fertilize them until spring.

Mine are a year old. I don't fertilize them. They get watered by the sprinklers once per week. They are mulched with pine bark, and three times per year, I sprinkle acid pellets from HD on them. They get full sun all day long.

Every month I braid them through the lattice. Last month, I even accidentally poisoned them with a double dose of bug spray. They are still growing over a foot per month. It's not my green thumb, it's their being suited for this climate.