Hi, all,

Here's my story of weirdness. This past spring, I ordered three dahlia bulbs of the semi-dinner plate variety. I received them and them promptly forgot about them completely. My wife was going through some stuff and found them... last month (end of September). She opened them and to her surprise (and my shock) two of them looked like they had a shot. She potted them up and put them in a south-facing window.

Color me surprised when they came up and started going gang-busters. So OK, now I have two young but thriving dahlias and we're only two days away from Halloween.

Here's my situation: I live in zone 6A, where the daylight fades dramatically as we head towards winter. I'm assuming I'll throw a grow light above these two plants and that that will sustain them through the cold and long nights. My biggest concern is about how long these plants can keep going in one unnaturally long "growing" season. If I still have vibrant plants in May and I set them outside, can they safely handle it or do I need to force them into dormancy, so that I don't "exhaust" them?

Thanks for any ideas or suggestions you may have!

Welcome to All Things Plants, @Kinsella217 !

That's really an interesting question, I wish I knew the answer for you... I will say that one spring my brother-in-law dropped off a bag of dahlia roots that had sprouts at least a foot long, which had been stored in his basement for 2 winters without ever being planted -- and they still grew well for me! So, I'd say dahlias are pretty tough and you have a very good chance of success with your "forgotten" roots!

People in warmer zones sometimes just leave Dahlias in the ground all year round.
I think yours will be fine.

As Caroline stated... Dahalias go dormant due to the temp, rather than any need for rest.
When I've grown them... I had to protect them from deer and voles, but the lengthy season just made them happy.
Provide lots of light, keep them warm enough, and I'd expect to see flowers over the winter.
Ok... Just googled them... Native to Mexico, I don't reckon they go dormant at all if the temp stays warm enough.