As a general rule, they will perform EXACTLY like roses do.

Some blooms will come within the height of the plant and some will grow higher, though usually dahlias do not bloom much higher than the plant. Perhaps 6-8 inches at most above the top leaves.

You can pinch the leaves after they sprout to 'widen' the plant and keep it from growing to its' tallest and then you get a bushier plant with more blooms. Or keep the main bud and pinch off the side buds to get long tall blooms.

Ultimately however, each plant has its own 'preferences' and I own neither Melissa nor OUTTADABLUE so I have no personal experience with them or how they tend to bloom.

hi davidinsf

when you say to pinch off leaves to widen plant...which leaves are you referring to...the sides?

David is probably referring to topping the plant. It is a standard practice to pinch off the top growing shoot after the first three sets of leaves have formed. It encourages lateral branching below, and causes a forking in the top growth. More branches = more flowers.

thanks!