Hi Welcome!
Many people plant dahlias before they have grown any sprouts at all. If you read the info at the Swan Island Dahlia site, they suggest that if your tuber has grown a long sprout, to snip it down to 1" when you plant it, however that is directed at people who havent potted them up first. I plant mine at what ever stage they are when I am ready to plant. Right now, some of my dahlias are close to 12" plants, some have just barely eyed up and started putting out roots, and everything in between. You just have to be really careful with the sprouted ones and dont break the sprout as they go into the ground. If the sprout breaks off at the base, it will most likely re-grow, but it will take a while.
I am in WI, so not much help when it comes to growing dahlias in the tropics. On another site I frequent there is a gentlemen from FL (not sure where) who talk of planting them out in Feb, his are full sized plants and starting to bloom now. He says his plants go pretty much dormant in the full summer when the heat really kicks in, and then begin flowering again in the fall. Apparently there are some dahlias that are ore heat tolerant than others, but I am afraid I dont have a list for you.
Good luck with them!
