Hi! click on Colorado Dahlia Society. They have good planting section, Steve in Baltimore

You can just put them in the ground after hardening them off- you can even take off the first row of leaves & plant them deeper than usual if you want-- kind of like planting started tomatoes. Dahlias like the temp. of the soil to be at least 60* to do well. Colder than that & you risk rotting the tuber before it sends out enough feeder roots to support the plant.

Thanks to you both. I'm afraid I wasn't very clear. The tuber sprouts a quarter-inch (or less) of green shoot, so I know it's made it through the winter. Can I immediately cover it in a 3-4 inch hole, like I could do with a hosta, and have the sprout push on up (soil temperature not an issue), or must I wait until I get enough sprout (5 inches or more) so that at least the topmost leaves are never buried? Sorry to be so dense.

It will push through the soil okay if it has not leafed out. Even then, it may loose the leaves and will push through. I wouldn't have the eye too deep though, certainly not 3-4 inches. The depth of the hole depends on the length of the tuber, but I personally try to keep the eye (sprout) at about an inch deep. These can always be hilled later, once the plant has developed well and you have removed the bottom leaves as suggested by plantlady2.

Wait a minute there Jroot, you have to enlighten me about 'the depth of the hole depends on the length of the tuber.' I always plant long, short, stout, skinny, lumpy, stumpy, smooth and sleek, eyed or sprouted tubers all alike. About 4-6 inches down in a prepared hole they go and get covered with soil; covered further with mulch later on.

What the theory on length vs depth? What qualifies as long? I wish I would have taken or saved a photo of the longest tuber I ever dug last year- a real champion of about 14 inches and its clump-mates were all more variety-normal 5-6 inchers. Very strange and the first time I've seen such a disparity on one clump.

Poochella, when I re-read I can see room for misinterpretation. Sorry about that. What I meant to say is, if one has a really long tuber, one will have to dig a little deeper in order to accommodate it. Remember, initially, I put mine in pots. I have some tubers that are at least a foot long, so I have to go deeper because I can't go wider than the pot. I see we agree on the hilling aspect however. That's good. When I take them from the pot, and plant them into the garden, then I plant them with the sprout end of the tuber about 2-3 inches initially and then hill later. Hmmm, I guess I overreacted a bit there. Sorry about that.

Thanks for clarifying that Jroot. Makes good sense for longer tubers. Have you ever tried cutting the longer ones off a bit? My head was in the earth and not thinking about planting in pots, although I am doing that RIGHT NOW (yippee) for the first time myself.

No problem :)