It sounds like you have just purchased the tubers, not as though they have been stored at your home over the Winter. Perhaps it is best if I tell you what I do.

First of all, dahlia tubers cannot freeze. After frost has damaged the tops in the Fall, I dig, select the best ones and store those in peat moss through the Winter months on the floor of a basement room.

My dahlia roots were re-planted this week. Here, any morning with clear skies, the temperature drops below freezing. However, those dahlia roots are no closer than 4 or 5 inches from that cold air. The soil protects them from frost and I could cover them more if severe temperatures occur but I don't remember having ever done that.

I have grown the small dahlias from seed, starting in the greenhouse. Never have the tubers gone in there during the Spring. Of course, May 5th is just a few days away. They hardly have time to break dormancy.

I have had a backyard greenhouse for over 30 years. My guide for temperature is from having worked in a commercial, rose greenhouse before that. Year-round, we kept the temperature no colder than 60⁰ at night and pushed up to 65⁰ during daytime. With ventilation and Summer air conditioning, temperatures were kept below 85⁰.

Small greenhouses are difficult to control during sunny mornings/days. The temperature can quickly soar into the 80's, even if outdoor conditions are too cold for plant starts.

I don't know if any of this helps.

Steve

Hi Steve,

this helps so so much!!!! Especially the part about planting them now. I was so scared to plant before it was over 40 every night. I started them in my garage with heaters and grow lights just the other day from boxes I put them in temporarily. It looks pretty funny but was just hoping they’d hang in there until whenever I can get them in the ground. Since they now have a bit of growth can I plant them now or should I wait a bit?

great advice for winterizing too, I was wondering where to store them after packing them up so basement it is! And the greenhouse… I heard from my old neighbor since I wrote this who had one and she said and I quote “it was the bane of my existence” lol! So I’ll be pulling this post back up next winter when I’ll be in a place to invest a bit more to start earlier.

I’ve attached a photo for your amusement 😄 (the boxes have hostas and stuff… temp until more pots come). I still have like 20 tubers on the way. I may have gone a little overboard. Oops!

thank you again!!!!!!!!!!

best,

beth

I live in Arvada. My zone is 5b. My dahlias are in pots also. I put them out for the day, then bring them back into the garage at night. I use a wire rack on a furniture dolly to make that roll in-and-out a bit easier on me. I think yours would be fine going outside, just be prepared to cover with frost cloth or turned over pots if we are going to get freeze / snow or the dreaded h-word.

I don't put any annuals (I consider dahlias to be annuals) permanently outside until Memorial Day and even then you have to be prepared for that weird snow we could still get.