Green House Temperture

Discussion in 'Indoor and Greenhouse Plants' started by CMeyers, Oct 29, 2013.

  1. CMeyers

    CMeyers New Member

    Messages:
    1
    Likes Received:
    0
    Location:
    Vancouver Canada
    Greetings

    I recently purchase and built one of those cheap steel frame and corrugated plastic greenhouses from Home Depot.

    My plan is to winter my geraniums and fuchsias over the winter in the green house in Vancouver.

    Question:

    1. At what temperature do I need to maintain the green house at so they will survive the winter?

    2. Can anyone advise as to the actual usefulness and functionality of such a green house?

    3. Can I start new geraniums with rooting powder this time of year (since I have to trim all the geraniums)?

    Thanks
     
  2. pmurphy

    pmurphy Active Member

    Messages:
    539
    Likes Received:
    53
    Location:
    Vancouver, BC
    To help you with your questions,

    1) It depends on what type of plants you actually have as to the temperature requirements and whether you can overwinter them.

    I find that, at this time of year, most greenhouses will keep the inside night-time temps a couple of degrees above the outside temp., but this will greatly depend upon the following:
    * location of the unit
    * size of the unit - normally the larger the greenhouse the more stable the inside temp.
    * materials it is made of, and is it single or double walled

    2) If you are NOT planning on heating the unit then usually the main function of a greenhouse at this time of year - if you are using it at all - is to provide a frost free area during the winter (a lot of plants can take the cooler temperatures but they are not frost-hardy). If this is the purpose you had in mind then it will now depend upon the plants you wish to store and their exact requirements. I'm currently storing some fuchsia begonias - begonia fuchsioides (zone 10-11) - that are still thriving and flowering inside one of my unheated greenhouses (a larger 16 x 9.5 x 8.5ft unit)

    * If you are planning on heating the unit then the minimum night-time temperature requirement for the particular plant is not something you really have to worry about, and you would then be able to grow year round.

    I know this is kind of vague but if you can provide additional information on the greenhouse then we might be able to give you more assistance.

    FYI, if you are planning on using it year round then I would definitely recommend an automatic vent arm to help maintain the summer temps (assuming the unit is larger enough to have a roof vent) otherwise you will have a hard time maintaining a suitable temperature as smaller units tend to get very hot inside when the sun comes out.
     
  3. vicarious1

    vicarious1 Active Member 10 Years

    Messages:
    314
    Likes Received:
    0
    Location:
    Burnaby North on a slope facing south & a view :-)
    I can't really give you a reply but I am on the same venture as you. Size L16'Wx6.5xH8' all wood and glass. All my tenants have moved in and suddenly we are getting a cold spell and I have many Kale and Collard green seedling I want to keep the green house above freezing. I keep some cycads and small fan palm, some Fuchsia and strawberries in pots on the floor they are all trimmed back but still have green sprouts.
    ANY ADVICE OF SPECIALIST IS WELCOME! THANK YOU.
    Maybe this helps. If your green house is tight!
    I tried this upside down "Terra Cotta" pot concept found online here: https://www.youtube.com/watch?v=jwElWD_qqCc I got NOTHING in temperature like those shown! I tried many ways with one 4" across 3wick candle for more power with one candle in a glass pot (like many from the stores. I did it with two big pots 12" and 10" across to heat a green house above freezing. Ambient temperature near 0C in Vancouver Canada. After 3hrs only the bolt was warmish and both pots still ice cold. They are standing on Terra Cotta bricks on a glass plate. So I guess it's only for an indoor a home maybe.
    My greenhouse is wood and glass http://smu.gs/1cYRrKvglass. and quite well insulated 96sq feet I guess it's only an "indoor" thing. Actually I want to grow my letuce inside in Spring to keep the squirrles from eating my seedlings as 3x last year. And prepare early seedlings for other plants in late winter early spring. Naturally not 100% airtight as its all an amateur job but all the wood is lined with 2layer 0.06 clear plastic and then 5/8 plywood again. I am welcoming any advice. Would you say as long as plants are covered they will not freeze? I put up an electric heater on minimum tonight just to make sure it will not I did install a brand new fire alarm and my mini heater is standing on a baking plate and us surrounded by 4 bricks nothing could tip it over and no animal of any size really could enter the room, that tight the building is. http://visualsenses.smugmug.com/Nat...95110_78GD5j#!i=2944875188&k=8cbbCZP&lb=1&s=A
    Forgot to say location is North Burnaby: Glass wall 100% south facing but somewhat shady as there are two huge pine trees. I trimmed one so the sun gets to the green house say from 10 till 1-2pm but no afternoon sun no way can't cut down the trees. Back walls are three layers cedar 2x plastic and 1x 5/8 ply wood ceiling is 3 conventional sliding glass doors one double glass two single and 5/8 plywood in between.
    Also working on getting 4 solar panels with cans as here https://www.youtube.com/watch?v=nuxanLdtwZQ BUT sadly that only works for day time so not much help as daytime the temperatures are rather less freezing in Vancouver.
    Any idea or concept exchange is welcome thanks. Unfortunately this once thriving UBC Forum has come to a very grand silence.
     
    Last edited: Dec 4, 2013
  4. pmurphy

    pmurphy Active Member

    Messages:
    539
    Likes Received:
    53
    Location:
    Vancouver, BC
    Unfortunatly at this time of year the best you can hope for in an unheated greenhouse is to keep it frost free but not necessarily above freezing. I would not recommend leaving young seedling - such as your Kale and Collard green seedling - in an unheated greenhouse unless you can provide them with a source of heat, such as a plant soil heating cable, or even like those used for heating pipes or roofs/gutters (I have even heard of people using incandescent Christmas lights - not LED because they do not heat up - to provide a little extra warmth, but I have not tried this myself)

    As for your cycads and small fan palm, it would depend upon the species that you have, but most should be okay in an unheated greenhouse - mine are doing just fine. I do not know about the fuchsia (are they annuals or perennials?) but the strawberries should be okay as they are quiet hardy (I currently have a couple of black strawberry seedlings only an inch or so high that are taking the cold without issue)

    If you really want to keep seedlings at this time of year I would recommend a heated greenhouse - or perhaps next year you could "section" your large greenhouse and set up a smaller area inside it that is double insulated and put a heater in the smaller area (I also have a 6x8ft double walled poly greenhouse that I keep heated to a minimum of 10C and this is where I keep my exotics and tenders at this time of year......just be prepared for a big Hydro bill)

    Sorry I can't give you better news....good luck.
     
  5. Dana09

    Dana09 Active Member

    Messages:
    152
    Likes Received:
    0
    Location:
    Vancouver Island BC
    I use my carport as a place to overwinter plants and to start things off in spring under lights as it is too dark otherwise.

    In winter the warmth of the adjacent house is usually enough to keep things from freezing but when the temps dip I have a light with a metal shade that I hang under a bench for added heat. In the country we do this in our pump houses to prevent pumps from freezing overnight, usually with a heat lamp intended for bathrooms. I use only an ordinary 60 watt bulb and it is enough to keep that section of the garage warm enough.

    One reason I place it under the bench is to keep the heat lower to start and also to keep the light from shining on the plants overnight so that none are fooled into flushing new growth.

    When it gets very cold I turn on an electric heater. Fortunately we don't get too many long cold spells here in coastal BC!
     
  6. vicarious1

    vicarious1 Active Member 10 Years

    Messages:
    314
    Likes Received:
    0
    Location:
    Burnaby North on a slope facing south & a view :-)
    Thank you. Great I saw a lamp like this yesterday at Home Depot, but hesitated. They showed me the bathroom heater bulb (many watts) and then a sort of metal shade to put it in like a "workers lamp" for onsite jobs. the lamp + the metal shade was still more expensive than my 29$ heater I already had. I did run an electric heater this night and this morning the green house was lets say "just sensibly above freezing". Would make a nice movie title eh? Thank you very much Dana for your input.
     

Share This Page