Make sure they get as much sun as possible. I planted some rhizomes in different spots in my yard - full sun w/southern exposure did great (though no harvest this year); partial sun barely grew at all. The difference was amazing.
I ordered 5 rhizomes from Northwest Hops last year - 2 Cascade & 3 Centennial. They were all in good shape when I got them, but only 1 of the 3 Centennials made it

Probably my error though.
I'd be interested in a wholesale purchase - looking to expand my selection...and I haven't been able to find Amarillo or Simcoe either.