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ziyakr

Where to overwinter dalia tubers?

ziyakr
12 years ago

Ok, I have read the recommended online sites and more than 25 pages of these forums but not found an answer to my problems (tho I have learned a great deal, and been mightily tempted by all your lovely gardens). I'm a pretty new gardener and this is my first year with successfull dahlias. I have 3 of the Mystic dahlias (2 yellow and a red) that have been doing really well all summer but now I'm nearly ready to dig up the tubers and try keeping them for replanting.

First question is: Where should I keep the tubers? My garage is not heated and stays the same temp as outside (winter temps in Kansas City can fluctuate wildly from 60F down to -10F) and my basement is heated to the same temps as the house (about 64 usually). Is it better to let them stay warm all season? My fridge isn't an option since it tends to freeze veggies, I wouldn't trust it with bulbs or tubers.

Second question: The plants are in wooden half barrels that I'm planning on removing from my landscaping this weekend (they are ancient and rotting) but we haven't had a hard frost yet and the dahlias are still blooming. How important is waiting for a frost and the foliage to die back?

Thanks for any thoughts you may have, and sorry if I've duplicated other forum posts!

Comments (13)

  • teddahlia
    12 years ago

    If you have an old fashioned root cellar, that would be ideal. Otherwise, most people store their dahlias in the garage and put them next to the warm wall that adjoins the house. Since it gets so cold in your area, I would cover them with as much insulation as possible. They cannot be allowed freeze. You could buy an inexpensive remote thermometer and monitor the temperature during especially cold weather. Bringing the dahlias inside the house during the really cold snaps would not harm them.

  • oscarthecat
    12 years ago

    Yes I have the same question.
    Is it absolutely necessary to wait for frostkill to dig my tubers.???? Steve in Stevens County

  • Linda's Garden z6 Utah
    12 years ago

    Swan Island says you should not dig until 2 weeks after a killing frost or mid November without a frost. Tubers dug too early are too green and will not store. I have not tried digging them early so I don't know if thats true or not.

    Last year I didn't get the killing frost until right before Thanksgiving.

    I store my tubers in the garage which is not heated but is attached to the house. It doesn't freeze in there but has got down to 36 degrees when it is in the single digits outside. I keep a thermometer in there so I can monitor the temps in the winter.

    Linda

  • mytime
    12 years ago

    Although I always wait for the first killing frost (I don't have what it takes to cut down blooming flowers in the fall), I certainly don't wait until 2 weeks later...the ground might be frozen by then! Because I've been gone, some won't be dug this year until a week after they were killed...I'm hoping it's not too late.

    I need to know if the new ones of mine that didn't have a chance to bloom (although they did have buds) will form eyes for next year. I've never had dahlias that didn't open before first frost before...hopefully this year was an oddity for them, because if they're always this late, I'll be getting rid of them. We had a late fall, so if they can't bloom by the end of September, it's adios to them!

  • Linda's Garden z6 Utah
    12 years ago

    Mytime, My show-n-tell did not bloom at all last year. I saved the tuber and started it early in the house this year and it has been blooming like crazy since the end of July. I believe your tubers should be just fine. I have one this year (Envy) which does not even have a bud on it yet. I have given up hope of seeing it this year. Next year I will start that one early too.

    Are the ones that didn't bloom, AA or A size blooms? Most of those seem to take a long time to bloom. Although my Kelvin Floodlight is a big one and it has been blooming since August and I did not start that one early.

    Linda

  • mytime
    12 years ago

    Thanks for letting me know about your show-n-tell; that gives me hope! 2 of mine that didn't bloom are As, but one is only a 4 incher, so I'm not sure what happened with those three.

  • mandolls
    12 years ago

    I cant store mine in the garage either. We can get to -30 on occasions, and even if it is 20 degrees warmer in the garage that just doesnt cut it.

    I have heard of people storing them on the floors of closets that are on the outer walls of their houses with good results, and in unheated attic crawl spaces. I have what used to be an attached garage that has been converted into a workshop. It heated with electric space heaters and kept at 55 when I am not out there working. The floor is just a concrete slab, so it is considerably cooler. I store mine in a couple of big plastic tubs on the floor in the corner, and they do very well.

    As for early digging. One year I was leaving the country for 3 months in mid September. I dug then and stored them before I left. It was not a problem.

  • sheryl_ontario
    12 years ago

    If you get temps of -10 your tubers will freeze for sure. What about an attic, if you have one. It should be cool up there, being unheated, but won't freeze. If they are really important to you and you have absolutely place to keep them cold and yet unfrozen for the winter, why not try to grow them in a sunny window as houseplants, potted? Would that work? Does the tuber need a rest period? I would cut it back severely before potting up and continue to cut it back throughout the winter to keep the growth small, then let it go when planted in ground. You could cut it back completely in early spring and then plant the tuber in the ground when the ground is not going to freeze anymore. It won't grow until the soil warms up so it will get a rest period then.

    This is all just hypothesis, of course. I have not done this, but have thought about it.

    I have a cold, damp root cellar in an old, old farm house, so storage is not a problem. It's the work and time involved in properly cleaning, dividing, labelling and wrapping that I have considered shortcutting by just potting up. Also I do lose a few every winter, especially the little ones, so have considered doing this with them.

    I often bring mine out and pot them up in late Feb/early Mar. They are large by the time I put them in the ground at the end of May.

    When potted up that early, I cut them back to keep the small until I can put them out. You could root the cuttings you take from it all winter.

  • grannymarsh
    12 years ago

    I believe that the two week wait after whacking/hard freeze is so that one can see where the eyes are. The tuber will want to start growing again and send up sprouts. Especially for a newbie, seeing the eyes can be difficult.

  • honnat
    12 years ago

    If you keep your house at 64 degrees, I can almost guarantee that your basement is cooler. Don't you think?
    I don't have a root cellar. But dahlias are the reason I shut all the heat vents in my basement. I keep them in a basement closet on the floor. I've put a thermometer down there in the winter and it gets into the 40's pretty easily. Then again, MN is a frozen tundra during most of the winter.
    I would never have the heart to cut down a blooming dahlia plant. If it were me, I'd wait. I would be surpised if the ground actually froze 2 weeks after a frost in any climate. Last year, I planted tulips in the snow! The ground has a lot of warmth and it takes some sustained fridged weather to freeze it up. Right?
    Either way, I would assume that if you cut your dahlias down and wait a couple weeks it would have the same affect. Either way, your plant is dead and your tubers are no longer giving energy to it - and that should stimulate the eyes.

  • ziyakr
    Original Author
    12 years ago

    Early spring follow up: I dug up and stored the dry, wrapped tubers in the garage and after an incredibly mild winter I took them out to check them last week. Of the 3 clumps only one had an eye and the other two had rotten sections (really gross btw). Not sure if they did freeze during the 2 really cold days we had, or if something else got them. So I potted up two pared down clumps in hopes of some growth and this morning was rewarded with tiny stems and leaves in both pots! Next fall I'm going to have dahlias and begonia tubers to figure out what to do with...maybe the attic this time? My garden is too small for 5 foot plants with 8 inch flowers, or to grow hundreds of tubers but this year I ordered tubers for a type called "Star Wars" that has the dark foliage I love so much.

    Here is a link that might be useful: Star Wars Pot Dahlia

  • mytime
    12 years ago

    2 of the dahlias that never bloomed last year formed eyes. The 3rd didn't even grow much of a new tuber...too skinny to make it through the winter (although I haven't given up total hope, yet!).
    Honnat, yes, the ground could be frozen here 2 weeks after first heavy frost. Normally, no, but last year we had an unusually late first frost. And the year before that, it was even later, but frozen ground was earlier than normal. I didn't get all my dahlias dug last year, as the ground just wasn't thawing out during the day. When we hit 25 at night, but 40 during the day, we're far more hours below freezing than above, and the sun just doesn't win. I've planted bulbs in the snow, too, but for us, snow in October usually means warmer weather than sunny skies do.