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swanzeyguy

Heated coldframe plans or ideas

swanzeyguy
20 years ago

Hi, I just discovered this site and have a question.I want

to build a good size coldframe, ( not to winter over, but

to actively grow veggies in these very cold New Hampshire

winters where it gets up to 25 below farenheit..I'm thinking

of using one of those small ceramic heaters and a

thermostat to try to keep temps 50 plus degrees..Has anyone had experience with this..Is it realistic..Can a uniform temperature be maintained in a coldframe using a thermostat ,or would a coldframe being smaller than a greenhouse fluctuate too much in temperature range..Any suggestions would be appreciated..Thx

Swanz

Comments (20)

  • faithling
    20 years ago

    Trying to heat and actively grow vegies in the northeast in a cold frame without supplemental light during the dark months (between Halloween and Ground Hog Day) sounds like a lost cause and a big waste of energy. I'd speculate that you'd use a lot less energy growing veggies indoors with grow lights.

    For season extending, I've tried working with cold frames in the past but found all the bending over, cleaning the snow off, and lifting the covers to access the beds (and vent them) felt way too much like work. I much prefer my hoop house where I can walk in and benefit from the protected environment along with my plants!

  • Bessboro
    20 years ago

    I am curious about Faithling's season extending with hoophouse. I am probably just across the lake from you seeing how we are both zone 4. Been a tough winter wouldn't you say? Anyhow, how long can you extend the season in the fall and when do you start up the hoophouse in the spring. Also do you use any supplemental heat or light or just natural. I'm thinking about a hoophouse but would like to get to know someone who could give me some ideas on what to expect for results and set me straight on how to proceed. I might add I really thought this forum would have alot more people intrested in four season gardening than it has had. Thanks

  • swanzeyguy
    Original Author
    20 years ago

    Thanks Faithling, I would definitely try a hoophouse if I had the yardspace. Your probably correct about the light needs of a coldframe..Just wanted a to have a small, actively growing space that would keep the winter doldrums away..

    Swanz

  • faithling
    20 years ago

    Yeah, there's no getting around it -- the winter doldrums can be brutal. But I get a lot of pleasure from my indoor plants in winter and have had little snibbits of flavor from potted rosemary, cilantro and arugula in the sunniest windows and nice colors and scents from forced bulbs, african violets and geraniums. Every little bit of plant life helps.

    I also get a kick out of growing belgian endive in a closet in the house and "harvesting" really good quality cabbage and root vegies from my root celar.

    Definately read Eliot Coleman's "Four Season Harvest" for other great ideas for getting through winter and extending the growing season.

    As for the hoophouse, it's just one layer of plastic over hoops with beds that were planted with cold hardy vegies in the fall. No supplemental heat or light. Some of the beds were timed for late fall harvest and others for spring. The beds are covered with remay for extra protection while overwintering.

    I've been checking every day to see if the warmer daytime temps are making any progress in thawing the frozen ground in my beds. Still hard as rock an inch below the surface. It's going to be another late start this year -- but the sun is getting stronger every day!

  • swanzeyguy
    Original Author
    20 years ago

    Thanks Faithling, it was Eliot Coleman's Tv show "gardening
    naturally" that got me interested in gardening.His books are
    great reading, I borrowed from library and read from beginni
    ng to end.Been a cold winter here in New England, but days
    are getting longer and brighter.
    Swanz

  • yooperjon
    20 years ago

    Hey folks,
    A tip for thawing your ground out earlier;
    Frost (Ground Freezing) enters into your hoophouse from the sides on an angle. Line the outside foundation with straw bales to slow, and sometimes eleminate freezing in mild years. Jon

  • micropropagator
    19 years ago

    I have noticed for many decades that winter onions, lettuce, and other winter-growing crops are 3 times as tall among falled maple tree limbs and other trash. This spring I falled to get a cold frame covered and planted. Weeds grew 3 times as tall in it as in the open space beside the cold frame. Any sort of winter protection is useful and gives you bigger spring vegetables.

    I regard my fall root crops as my most important garden. I have been eating from my August turnips since September and it is now May 15 and they will be useful until June 1 this year from the root cellar. Asian winter radishes do not last beyond May 1. Meanwhile, I am eating the seedstalks of turnips that I left in the garden overwinter buried under leaves.

    Harold Eddleman

  • swanzeyguy
    Original Author
    19 years ago

    Thanks John..Something like that is about what I was thinking . I have the same problem with ordinances , and just wanted to have fun growing something during the cold months..PUTTING IT up on sawhorses is a great idea, helps with the snow we get around here.
    Swanz

  • plantman532000
    19 years ago

    Hey Swanz, Check out the Accessible Garden forum! There is a post from June 3 from cyngbeld with a link to what they called an accesible cold frame. It is a site from Western Red Cedar Lumber Association. I checked it out and WOW! It looks great and could easily be insulated and set up for winter growing just like the frame I made years ago. Only I'd make it bigger than the plans call for, and add a solar vent opener like I used before! LOL Just go to the site and you can even print out the plans. Just thought you'd like to see it. Good growing.
    John

  • amin
    19 years ago

    I recently read a great book that may interest you titled the solar garden. They recommend creating an insullated bed by digging the edgesinto the dirt, and insulating this. You can create a passive heat supply with a black barrel of water that will collect heat in the day and slowly release it at night. They have a design for insulated solar pods, (but I may try to do something with 2 layers of old storm windows insulated w/ a couple layers of bubble wrap between. )

    Its best to cover the winter beds at night.and you are supposed to keep the snow off the top. (but leave it around as this is extra insulation)

    Also I have seen other plans if you have a south facing slope, you can dig in and create asunken bed with the top slanting twords the south, as underground the temp stays an even 55 degrees (supposedly)

    There are many ideas I have come across for heating (to many to list) but the greater problem would seem that depending on what you want to grow there may be insufficient light in winter. I have heard great success stories even in my zone four for growing lettuce, arugala, spinache, leeks...and other cold tolerant veggies, most of these suggest the plants still go dormant in Dec. and Jan.

  • swanzeyguy
    Original Author
    19 years ago

    Thanks John, gonna check out that site..I promised myself I'd build something this summer..Thanks Amin,,I think a black barrel of water would just turn into a block of ice without supplemental heating.I've read about the sunken bed concept before, the only problem being, ( as you mentioned) limited light..
    Swanz

  • Millie_36
    19 years ago

    Swanzeyguy, I remember seeing it done in Northern Germany, but not sure "how" it was done. The man had a greenhouse/green grocer operation going all winter. Fresh lettuce mostly...but lettuce is less cold hardy than the cabbage family. He had berms of soil built up in a field with the cold frames facing south...other than that, I can't say. I suspected that he might be using hot manure buried under the soil in the bottom of the frames. My grandfather told me that was how they built them for starting early season plants...he grew up in Illinois. Chinese veggies, lettuce, cabbage, spinach, kale, etc. needs less light. If you can keep the soil temp at 55 to 60 degrees, it doesn't take much cover to keep them from freezing. We use hot water lines under beds in an unheated greenhouse. Only need to run the hot water when it really gets cold... then on a bad night, toss some floating row cover over the lettuce, spinach, etc. It traps the warm air rising from the soil. Only loss has been leaves that touch the plastic on the sides of the greenhouse. The beds are built right up against the outside cement block foundation. We did line it with some 1 inch styrofoam. Square bales of hay would be better, but haven't needed it. I have used hay bales to build a raised cold frame, but not in country as cold as you deal with.

    Works great for winter propagation of woody plants...keeps cutting bottoms warm for rooting while the tops stay cold, so they will stay dormant.

  • swanz
    19 years ago

    Thanks Millie, it's fascinating all the different techniques
    that can be used..That method of propagating woody plants
    sounds like something I'd like to try.

    Swanz

  • Don_NS
    19 years ago

    Hi Swanz
    I have a heated cold frame that I use for starting flowers and veggies. It's made of 2" thick styrofoam that is framed with wood.I use a 1500 watt ceramic heater that is operated off a thermostat I also have a ventilation fan also operated off a thermostat to help with cooling. The box is 4' X 8' I use three wood framed sashes double glased with plastic to cover it. I has worked well for me for the last 4 or 5 years.
    Don

  • swanz
    19 years ago

    Thanks Don, I bought one of those small ceramic heaters,just
    gotta get a thermostat,been checking around, they're pretty
    pricey, 50.00 dollar range and up.

    Swanz

  • markapp
    19 years ago

    Another book that has some great plans for frames and cool season gardening is gretchen poisson- solar gardening. frames look a bit pricey but innovative and quite nice.

  • byron
    19 years ago

    Swanz

    A combination of old and new.

    Near the ground I use peanuts for insulation to get some R value

    For old, I used horsemanure as in the Hot bed concept.

    Horsemanure plus a few 40w bulbs within a small area, 2" styrafoam for a night cover will keep your plants above 50F when the outside temps are 18F

    Byron

    Here is a link that might be useful: My GH

  • swanz
    19 years ago

    Thanks Byron, enjoyed those photos.

    Swanz

  • bluemill
    19 years ago

    i made plastic 6' "pup tents", which are easy and work well. e mail me if you would like more imfo. and i use dark colored buckets of water, which collect heat during day and release at night. got idea from elliot coleman book.

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