Tamar
This is from a Texas grower in a Warm Climate Dahlia Growers FB group that I'm in and I thought it might be helpful for you, with the probable exception of the "spring rains" part.
"I am in Houston and there a few of us crazy enough to grow dahlias. Much of the common dahlia growing advice is not applicable, or even counterproductive for us. I commonly recommend these tips for our area:
1) Plant a little deeper to better insulate from heat
2) Shade cloth (50% or so)
3) Mist the plants during the heat of the day with overhead sprinklers/hose.
4) Plant in locations for morning sun and afternoon shade
5) for our Houston specifically, watch out for those spring rains, they WILL drown and rot your tubers.
In southeast Texas we have a window from Feb-Jun, then Sep-Nov/Dec. Don’t be suprised if some larger dinner plates don’t have time to bloom before the July heat cooks them.
You can grow them straight through but you should probably plan on cutting them way way back for the heat wave Jun-Sep or so."
