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artbysheryl

growing dahlias in the house

sheryl_ontario
14 years ago

I have some dahlias that I grew just recently from cuttings. They have roots but no tubers yet. I have them in pots now and would like to keep them growing on the windowsill throughout the winter. Will they survive like this? I don't expect them to grow much or flower, I just want to keep them alive until they can go into the garden in the spring.

Comments (6)

  • teddahlia
    14 years ago
    last modified: 9 years ago

    I have done it twice successfully and failed once. I had the plants in 2.5 inch pots. They were on our South facing window ledge. They grew to about 12 inches tall but very skinny. This last year the plant got powdery mildew. I cut it back in the spring and took three cuttings and two rooted, the other died from the mildew. The two cuttings were planted in with my other dahlias and spread powdery mildew spores to the entire row. I had never had to spray fungicide in July before. The fungicide worked and we took one of the flowers to a dahlia show.

    In other words, the dahlia you want to grow through the winter better be very irreplacable as it is hardly worth it.

  • sheryl_ontario
    Original Author
    14 years ago
    last modified: 9 years ago

    I have some rooted and growing cuttings recently taken that I want to overwinter. They don't have a bulb yet. Will they survive if I leave them potted and put in dark cold basement with the other dahlia bulbs?

  • jroot
    14 years ago
    last modified: 9 years ago

    not likely. Sorry to say, Sheryl.

  • sheryl_ontario
    Original Author
    14 years ago
    last modified: 9 years ago

    So, I guess I'll just grow these on the windowsill over the winter and see how they do.

  • linnea56 (zone 5b Chicago)
    14 years ago
    last modified: 9 years ago

    Some of my shorter ones are in deck pots. I try every year to bring them in, especially when it seems like they are just getting rolling with lots of buds when frost is imminent. I have tried going on 5 years at least.

    Every year they either:
    - become spindly and peter out and die (this in a room with a skylight!)
    - get mildew and die
    - shrivel up for no apparent reason and die

    I think they just cannot get enough light or adequate air circulation indoors. If you have a greenhouse or sunporch Id be more optimistic.

  • sturgeonguy
    14 years ago
    last modified: 9 years ago

    Sheryl,

    There's a lot of variables that decide whether they will grow or not. But start with this; Dahlias originate from Mexico and don't die completely back each year in the wild.

    If you search through the forums for my threads from last year, you'll see the type of environment I created to over-winter growing Dahlias. My first attempt (last fall) ended miserably due to spider mites.

    Regardless of pest or disease, you're going to have the simple problem of light. Assuming the soil is good, and you provide them sufficient (but meager) water, the only thing lacking is adequate light. Light of the right temperature, duration, and direction. This is why many find their Dahlias get tall and spindly inside...the Dahlias are reaching for better light.

    I built cabinets that each had 4 x 4' 6500 degree Kelvin T5 flourescent bulbs ~12" above the plants (Bustan in Toronto can fix you up and they were great). Sunshine simply isn't going to cut it, it will simply tease the plant into thinking..."if only you could reach over here, or there..." and so they put their effort into growing tall and reaching.

    Under sufficient lighting (which was on for 14-16 hours a day), they thrive. If you don't want them to get too big over winter, just give them less duration (but it must still be the right temperature light and close enough to them.)

    If you were doing a single plant, you could easily do this on the window sill with a plant light over it and a timer on it. No need for cabinets and tons of lighting equipment like me. I was growing 100 plants inside.

    Now to the problem I had last year, spider mites. I found a company in Stevensville, Ontario, who supply predatory mites. They have many to choose from, and they were extremely helpful in deciding which one I needed based on my environment and the spider mite type I had.

    After my fall crop died, I cleaned everything, tossed all my soil, and almost all of my indoor plants. I bought new tubers and started from scratch in March this year. I didn't, however, realize that my Cannas, which were doing great, were haboring the spider mites. No noticable webbing or damage.

    By the time my new Dahlias were getting to 3-4" tall, the spider mites re-appeared. I cut back my Cannas to get rid of the majority of the spider mites, and ordered the predators from NIC. They also recommended I grow a few pole bean plants near my Dahlias, as spider mites will prefer the pole bean to anything else apparently.

    Well, one application of predators (essentially sprinkling them over all of the plants) and my spider mite problem disappeared.

    I will be bringing many living Dahlias and Cannas in this fall to over-winter alive. My plan is to get predatory mites when I'm ready to bring in the plants, and will sprinkle them once inside to ensure I'm not allowing any I bring in to survive.

    So, get yourself a plant light and go for it. With a plant light, there's no reason to think you can't make it bloom in the dead of winter, which would be lovely.

    Cheers,
    Russ

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