How long will large dahlia plants bloom if started early?
What I'm wondering here is, what if you are able to start tubers indoors, in a greenhouse with good sunlight and warm temperatures, so that when late May rolls around and it's time to plant them outside, you already have 2 foot high plants with at least 1.5 to 2 months of growing time since the tubers were planted in pots. Will those plants still actively and continuously flower all the way til the first frost in October or early November like here in Delaware?
Dahlias are supposed to bloom after a certain amount of time growing(weather permitting), and many varieties of larger dahlia plants will start blooming after 72-90 days of growth. But if you are able to start them indoors 1.5 to 2 months earlier, will they bloom for an extra 2 months longer than if they had been planted in the ground on late May as tubers? Or will the flowering tend to weaken and peter out earlier? I always notice that they tend to flower almost in spurts, where you'll have periods of heavy flowering and periods with light flowering.