Rolacoy,
30" is not really tall for a dahlia and I'm afraid they often have to be staked...but that's OK you can always make sure the stake is not visible. I'm sure everyone here would agree they are well worth it!!
How did your seeds turn out? Did you get some interesting flowers?
Janice

The ones that I grew from seeds came on very slow but are blooming a little now. I started them in my greenhouse in about February, they did not get very big in the greenhouse. I planted them after I knew it would not frost, maybe mid March. Only about 5% of the plants matured and I have had some blooms. They only got about 18" tall. I guess that they will live thru the winter and be bigger next year.

I did not have a lot of flowers on the seeded ones or the tubers. However we were away from home from July 15th to August 10th so I don't know how they bloomed during that time. I had someone watering during that time so they probably did not get as much water as if I would have been home.

Next year top your tuber dahlias and what I mean by this is to pinch out the main growing stalk just above the last set of leaves when the plant is about 12" high and has 3-4 sets of leaves. This will cause the plant to put out laterals and will make it a bushy plant and somewhat shorter than if it is not topped.

Corralitos Gardens in California has a number of bedding dahlias that will stay short and not need staking. A couple I have grown and would recommend are Jazz, and Princess Paige. These both grow well in our Southern heat.

A dahlia growing guide for Southern Gardens is available on the Dahlia Society of Georgia website. Click on the DAHLIAS THAT GROW WELL IN THE SOUTH PAGE.

Here is a link that might be useful: Dahlia Society of Georgia