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I'm in a quandary -

YviestevieYviestevie Kingswinford, West MidlandsPosts: 6,037

Hi folks, I have a v small (4' x 6') alluminium greenhouse that I decided would stay unheated. I have only had the greenhouse for just under a year.

Now that seed sowing time has arrived I have a bit of a dilemma.  I don't think the seeds I have sown will be ready to go into a cold greenhouse for a while. (I expect to be able to thin out and pot on in a couple of weeks or so). 

I also have a number of starter plants including verbena and pelargonium,  that are of a good size but again I'm worried about putting them straight into a cold greenhouse just yet.

The window ledges in my conservatory are full and it seems to defeat the object of having a greenhouse if I can't put them in.

Question should I buy a small heater and if so any recommendations.  I cant afford an all singing and dancing heater but would like to be able to control it thermostatically.


Do I risk putting the starter plants into the greenhouse now.

Any help/advice would be gratefully received.


Hi from Kingswinford in the West Midlands


  • Kitty 2Kitty 2 ManchesterPosts: 5,150

    Hi Yviestevie, I can't advise on a heater as I don't have a greenhouse.

    I maximise growing space at this time of year in my conservatory by putting up just the frame of one of those cheap greenhouses to hold seed trays.  The plastic covers are a bit rubbish anyway but the shelves help me cram in an extra 8 trays.  I have a tiled floor so any drips or mess are easily mopped up.  I also use windowsill propagators. 

     I dream of a small 6x4 greenhouse.  Maybe one of the allotment folks could advise on using an unheated greenhouse, I assume that's what they have on their plots.

  • FruitcakeFruitcake Posts: 810

     I have two greenhouses. One gets sun all day and the other for about half an hour in the morning. As the year moves on, the sun levels even out a bit. Up to today, they were both only being used in the winter to house my tender plants. Now they're both cleared out, why are all my seedlings still in the house? image Because I'm convinced that they are better off in the house until they have got enough leaves to go outside. I have shelves everywhere in the house with seedlings and potatoes on. 

    I agree totally with the greenhouse shelves. They will make life so much easier for you. On sunny days you can put them outside and bring them all back in at night. 

    Its not forever image

  • ButtercupdaysButtercupdays Posts: 3,218

    A small greenhouse fan heater is ideal. My current one is Montana 2000  (Biogreen) which I bought when I purchased my greenhouse from The Greenhouse People. They do others. It has a frost setting, which is all I use through winter, greenhouse bubble wrapped. In spring, as you say, you often need to get going with more tender things, so I turn the heat up a notch or so, depending on what needs the heat. I often leave the bubble wrap, as nights are still cold, but also it diffuses the light and helps protect delicate leaves from sunscorch. As Kitty says, the mini greenhouse is useful for seed tray space. My GH is already full with overwintering plants, potted up dahlias, pot and house plants and new bare roots getting some TLC to get them started. When those can all begin to be hardened off, there is more standing room for seed trays inside, so it goes outside to a shady, sheltered spot for hardening off and growing on of all the new plants

  • YviestevieYviestevie Kingswinford, West MidlandsPosts: 6,037

    Hi Folks, thanks for your thoughts,  I'm thinking of getting hubby to build me a cold frame so that all the overwintering perennials that are slightly tender can go in there as they don't need extra heat.   I could then move the starter plants into the greenhouse if I got a small heater which would then allow me to use the conservatory window ledge for heated propogator and  seedlings.

    My conservatory is used all year round as a dining room and it has a bed settee for visiting family so I cant really put up temporary shelving, it also has seagrass carpet so it wouldnt be good re watering etc.

    I'll have a look at the Montana Buttercup.  I got my greenhouse from The Greenhouse People and found them to be very helpful and reasonably priced.  Once, again thanks for responding, it is appreciated.

    Hi from Kingswinford in the West Midlands
  • lydiaannlydiaann Posts: 284

    We converted a summerhouse to a greenhouse simply by replacing the roof; it's of wood (red cedar) construction.  I've left it unheated since we've been here (3 years).  Last year I decided to sow seeds from my hollyhock, penstemon, lupin and aquilegia (I did it as soon as I collected them, I didn't dry them out or anything as they appeared to be dry enough).  Once sown in the pots, I scattered the tops with fine grit then kept them watered, cutting down on the watering as winter came in.  All these were left in the greenhouse throughout the winter  - in fact, they are still there.  And all of these, without exception, are now growing well (around 6-7 cm high) and I will have loads to put out in April when it's warmer.  If they grow outside and they are perennial, then it stands to reason that the seeds will quite happily grow in an unheated's really shelter from hard frosts and winds that they require until they grow up a bit.  After all, Mother Nature provides a self-seeding mechanism for these plants and She doesn't baby them at all!

  • Tropical SamTropical Sam Posts: 1,488

    You are lucky to have electricity in the greenhouse. I have to have a solar light and paraffin gas. Paraffin only takes the edge off of low temps by a few degree I am finding image

  • BrummieBenBrummieBen Posts: 459

    Ok, I have a 12ft x10ft greenhouse, I insulate about 3/4 and then have bubble-wrapp 'doors' . I have two of these, on a stand I made out of some wood lying about, so they are back to back facing out in the middle of my 'tent'. These heaters cost like 3 or 4 pence a day to run continuous, so for me less than 10 pence a day!! Imagine my surprise a couple of years ago when first rigged up, to have over wintering geraniums flowering in march!!!! I then bought a mains plugin thermostat and rigged an extension off that to the 2 heaters.. ever since, no matter how cold, the greenhouse never drops below 6/7 C all for the princely sum of maybe 6 pence a day!!! Best way to heat a greenhouse ever!!! Very cheap to buy, very cheap to run, can't lose!! Best of luck! 

  • hogweedhogweed Central ScotlandPosts: 3,991

    I use a soil warming cable in my greenhouse. It is very economical to run and you are not heating wasted air space like a fan heater. When it is cold at night, I fling a bit of fleece over the seed trays to keep the heat in. I find I only need to run it for the month of March, after that all is well (and I only start sowing at the beg. of March).

    'Optimism is the faith that leads to achievement' - Helen Keller
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