Sorry the snacoons have found you.

You say 3 hours of full sun- does that mean you get part sun, or dappled sun more hours than that? That would be my first guess, is that the dahlias would like more sun to be their best.
Second, did you top them? Pinch out the center growth when about 4 sets of leaves were formed? That would make the plant develop those little side shoots that go on to fill out a bush and give you more blooms. I was bummed that I found three today that I hadn't topped at all! They are tall and skinny. Wish I was. I feel short and like I'd like my knees to be stretched out on an old fashioned rack, having been bent for the past 8 hours watering.

Poochella - you're too funny! I feel tall but unfortunately the skinny part escapes me. Guess I'm a snaccoon too.

I bought mostly 15" to 20" dahlias to start with. And they are getting full afternoon sun from about 12:30 to 2:30 or 3. They often wilt a bit and then recover later, even though they are not dry. I have to confess after seeing the prices, and having watched caladiums do so poorly here in containers (soil temps not high enough last couple years), I bought my dahlias for $8.49/9 tubers at Costco in February. They have names and they've bloomed true to the pictures but I'm sure these are run of the mill dahlias. Then again you never know, Costco does surprise sometimes. Anyway, they have flopped a bit out of the containers but have remained about 15" to 24" high and thick and green. I gots lots of green. I wants more flowers. I thought Bulbtone and tomato fertilizer would be the right thing to do. I will not fertilize again - I think they've had enough. What I was wondering is whether August will bring the blooms - are they just not quite in season yet? It's sure been HOT enough for tubers, just not sure they are getting the right sun requirements.

The ones that have really taken off are 2 small singles, a ruby red with yellow center and a very white with yellow center. I've cut a lot of them and they are behaving just like CCDahlias said they would - putting out more buds and blooms. I have enormous pots of Verbena Bonariensis towering over their heads and I rather like the combination. Very lush. The ones that are hanging back are Mum-type purples. I suppose I could go look up the names and I bet some dahlias are more prolific than others. If somebody can answer that I'll go hunt up the names.

But I was wondering, if dahlias are originally from Mexico, I wonder what part? Most of Mexico is beastly hot and sunny in the daytime, and often dry as well - think bougainvillea. I suppose around Mexico City where the elevations are higher they might moderate the temps. I would think a tuber would rot in the high humidity jungle areas along the Gulf Coasts. Well if anyone knows, I thought that might give a clue as to what environment to duplicate.

good grief - I hit the send button before I answered your question Poochella. I was rambling a bit wasn't I? No - I didn't pinch. Because I bought short bushy types to begin with.