Most Dahlias are hardy to USDA Zone 8 where they can be cut back and left in the ground to overwinter. In Zone 7 dahlias typically overwinter in the ground depending on soil drainage and severity of the winter. Nitrogen or not I don't think you can expect a Dahlia to survive a zone 4 winter. The good news is that the tubers are like small potatoes and very easy to lift and store. Select a sunny (minimum of 6 hours) location much like for roses. Dahlias grow best in a deep, fertile, well-drained soil with a pH of 6.0 to 6.5; they are not tolerant of water-logged soils. Mine bloom well for me no matter what fertilizer I use....or never use. I have heard it recommended that you use a bit of 10-10-10 around them. Why you didn't get any rebloom I cannot say. It is recommended that faded flowers should be removed to encourage continuous blooming. HTH Ronda

Luxrosa -- 'Georg Arends' did get hit with blackspot here in NJ -- as did almost all the others, with a few interesting exceptions, notably 'Golden Buddha' bred by Paul Barden, which has remained PERFECT save for the occasional mildew on a leaf or two (and this says A LOT about a rose in the mid-Atlantic), and the only spray I used was neem oil, baking soda and dish soap in water as a modified Cornell mixture a few times up until late June. 'Georg Arends' shed damaged leaves rather quickly, and did get to an "almost naked" stage once, but leafed out again rather quickly. Keep in mind that this is a rose that came only this Spring as a band from Vintage. I let it have only a few blooms, and yes, they were VERY VERY fragrant -- strong, sweet "old rose" that is said to be "pure Centifolia" but being as I've never smelled a Centifolia, I can't comment on the comparison. They were a monochrome, unshaded pure pink, shaped like a typical fat Hybrid Perpetual cabbage but with the folded-back pointed-petal look of a Hybrid Tea. Considering its ancestry (it's about 3/8 Tea and 5/8 Hybrid Perpetual), that makes sense. Oh, and the plant is completely thornless -- I still haven't found the first thorn. It's growing as though it will be a short climber, or at least something that would do best with a little support -- like against an open picket fence -- so I have it where I can attach it to the lower part of the deck railing as it gains a little more height. I think much of the vase-life is a result of it taking a couple days to fully open, due to how many petals it has. Once opened, it holds up another couple of days. I cut one in the "loose-but-closed" bud-stage, sepals fully back, and gave it to my neighbors who share the yard with me. They kept it in a vase inside right by the window where I could see it while working in the yard, and I watched it unfurling over a couple days. By about the fifth day, it started looking as though it was finally past its peak. And I can't imagine they did anything more than stick it in a vase with plain tap water. If you can't find a plant by Spring, let me know and I'll try rooting another piece of mine. I was hoping to interest Linda Loe of Long Ago Roses in growing a few rooted cuttings of some things I picked up from Vintage which don't seem to be available elsewhere, so at least they don't disappear from commerce. 'Georg Arends' was one of them, so I was going to root a few anyway. HelpMeFind has Pickering as one of the other nurseries carrying it, but it's not on their current HP inventory on their website (perhaps they used to carry it?). Hortico may be the only other way of getting it in the US, though once again, I don't see it among their current HP inventory. :-) ~Christopher When it arrived and was repotted, April 25, 2013: First flower I allowed to open, May 22, 2013: A pic showing 'Georg Arends' on the left ('Nouveau Monde' on its right), taken September 2, 2013. At this time, it's recovering from going naked. This post was edited by AquaEyes on Sun, Sep 29, 13 at 2:09

Poochella, thank you - that helps a lot. I'll repot them into milk cartons as I'd planned, and water them sparingly. They're all coming up and the leaves look really good, so I can't have screwed things up too badly yet. :-) I have a heater in the greenhouse - it never falls below 50 (normally it stays around 58-60 at night and on cold days, but if it drops into the teens at night, it gets down around 50 or so). So freezing isn't an issue at all. I have veggies and annuals growing out there right now that I started from seed - a freeze in the greenhouse would be a complete disaster for our gardens this year. Russ, I did say 13 hours of "daylight", not "sunlight". My greenhouse is situated where the sun hits it very early in the morning, and is on it all day, no trees or anything shading it at all (doors and vents stay open all day on warm, sunny days to keep the heat managable between 70 and 85 or so, and there are fans running in there 24/7). There are about three microclimate zones in my yard - the greenhouse is in the warmest, full sun microclimate, where I have roses (my favorite flowers) starting to leaf out already. I have all manner of annuals and veggies growing out there in the greenhouse, and none are getting leggy at all, so I'd think that if there's enough light for tomatoes, there's probably enough light for the dahlias to get started. They're coming up fine, as I said, the leaves look good, so I think they're getting plenty for now. Obviously as the days get longer, they'll have light longer. I'm not on the "mountain side" of the state - south-central Montana (where I live) is closer to a desert than the cooler mountain regions in the western parts of the state. And I never said I didn't like dahlias...I said my husband loves them (which he does). I like the flowers, but I have more of a passion for roses personally (don't have to dig them up in the fall). Maybe I'll fall in love with dahlias after growing them for a season or so - but I won't know if I don't try! My hubby doesn't care much for typing or forums, and he would never "make" me ask anything, anywhere "for him" (he wouldn't have asked for himself either...he'd just throw them in a pot and let them grow or not, as his dad does). I asked of my own free will, because I was interested in how to get them the best start possible. It's my nature to jump into whatever I decide to do with both feet. I am interested because I love my husband, he loves dahlias, and that makes me want to have some in the garden for him, regardless of some extra work in spring and fall. Have you never grown something just because someone in your family really likes it? In any case, thanks for the advice. I'm sure we can get the dahlias off to a good start this year now.

Blondie, those dahlias look beautiful. I hope you post lots of pics so we can see how they look. I need to get to my Costco and see what they have left. I got a membership there last year but hardly use it. We go to Sams Club which seems to have more of what we buy than the Costco does here. I dont know why. Costco is newer to this part of FL so maybe they will get more stuff in eventually. Pat, Of the two times I tried growing Cafe Au Lait: one time it never came up and the other it had a few blooms then died right away. I wonder if likes a cooler or less humid climate. There are apparently, dahlias that are better for warmer climates. I saw a list somewhere... I googled Breakout and its lovely! I love those soft colors. I realized most of mine are brighter colored hmmm. I think you will like Pacific Ocean! I have never ordered Dahlias from Brecks yet. Good to know about all these sources!! Kaleidoscope, our Aldis never has any plants or bulbs. I hear of the ones south of us having roses and all kinds of stuff. I haven't tried Old House Gardens yet, let us know, if they are a good source! Has anyone grown Bedhead? That is the cutest craziest flower lol. So tempting. How about Cupcake? I need that one lol. Looks to be soldout so have to wait till next year. Booo