What size is good for a greenhouse?

Discussion in 'Gardening & Plant Propagation' started by Kazahleenah, Jul 23, 2005.

  1. Kazahleenah

    Kazahleenah Disgruntled citizen

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    I'm building myself a greenhouse this fall, and am contimplating what size. I am leaning toward making it the same size as my shed that it will be sitting next to. (10X12) Is this too small for typical gardening? I plan to start my flats out there, (approx 20 plus flats) some of the longer season plants, (watermelon, sunflower, etc) I live where it gets cold, so will have to heat it. Is this too big to heat economicaly? What ways would you all suggest to heat it? It will have electricity to it.

    Thanks everyone!

    Kaza
     
  2. vtfarma

    vtfarma Well-Known Member

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    10 acres would be a good sized greenhouse but then again so would 10 x 12. We installed a vent through the wall gas space heater for the neighbor up the road. His greenhouse is 12 x 8 or so. Worked great for him... plus his positioning is to the south and sheltered from all the wind and weather.

    Good luck.

    Laurie
     

  3. Kazahleenah

    Kazahleenah Disgruntled citizen

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    how cold does it get there? This location is also protected from the main weather winds, but it gets dern cold here...

    Kaza
     
  4. moonwolf

    moonwolf Well-Known Member

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    I have a 10 X 12 greenhouse. For the 2 tables to hold the flats I made from cedar strips are 2 ft. wide and the length of the greenhouse (12 ft.) They will hold easily 20 trays each, underneath. So, for the 'typical' garden this is plenty. To heat it, I was lucky to have the outside wood buring boiler furnace, so I tied in an underground hot water line and had a small circulating pump to a couple of baseboard heat exchangers. The setup materials for this was about $200 inclunding the pump. For cooling, I had several sprinkler heads above that were hooked up to a lawn sprinkler timer so it could come on for a few minutes every so often when it was hot, or to automatically water the plants with a fine mist spray. You could program the timer howver many times to start and for how long each time. That setup with the programmable timer was about $100. The greenhouse itself I bought a kit made with corrugated plastic and aluminum frame. The base was a solid pressure treated wood on a 6 x 6 outside perimeter frame. It's still standing.
     
  5. yellowlab2

    yellowlab2 Well-Known Member

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    If greenhouse are like pole barns. build twice as big as you think you need. or as much as you can afford, whichever comes first :D Bob
     
  6. moonwolf

    moonwolf Well-Known Member

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    Actually, compact is better for greenhouse. Just enough space for the plants is more efficient and cheaper to heat or cool down. You don't want to waste energy on wasted space. I have another small green house in addition to the 10 x 12 which I can start holding plants if the bigger greenhous is full.
    Unless you need commercial growing space, a smaller greenhouse will suit needs for even the larger gardening ambitions to a tee. :)
     
  7. Hank - Narita

    Hank - Narita Well-Known Member

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    Ours is 12' x 12' and our neighbor's is twice as big. It's a matter of personal preference.
     
  8. Kazahleenah

    Kazahleenah Disgruntled citizen

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    :D will seedlings grow if the "shelves" are two high? OK, call me dumb, but I've never had a greenhouse before... the farmhouse had a room full of windows that was basically my indoor greenhouse. Sorry for all the silly questions folks..

    Kaza
     
  9. moonwolf

    moonwolf Well-Known Member

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    Here is what I do to start seedlings and use of the greenhouse.
    First, when it's spring and too cold in the northland, I started seed in the house or basement where it's warm. Cheap fluorescent shop lights are hung a few inches above the trays with seeds. Otherwise, the seeds will stretch and be weak if not enough light to grow. I also have the lights on a timer so the emerging seedlings get 12 hours daylight and you 12 hours dark.

    Once the seedlings are to be transplanted or when the daylight is long enough by May up here, I transfer to the greenhouse. Yes, you could start seedlings in the greenhouse also, but you have to be vigilant about temperature and moisture.

    The tables in the greenhouse I have stand about waist high. Below that are a lower level to put trays for plants that are started. They should get enough light if your greenhouse is well exposed to the sun. With the 2 levels on 2 tables, I can manage about 70 trays, and then there is extra room if needed below the lower table level on the floor. I have had that greenhouse and the other one that is 6 X 8 completely full, especially when having started flower plants, asparagus seed, cucurbit transplants (take more room), etc.