Using heated propagators.

Discussion in 'Gardening Discussions' started by Purple Streaks, Mar 15, 2025.

  1. Purple Streaks

    Purple Streaks Gardener

    Joined:
    Aug 13, 2012
    Messages:
    599
    Location:
    Sconthorpe
    Ratings:
    +873
    How is the best way of using a heated propagator?
    I have an heated one.
    For sowing seed mine seems to get too hot, am I supposed to take off the lids to cool down .?
    I thought I would be able to adjust the temperature, but it's set .
     
  2. Philippa

    Philippa Gardener

    Joined:
    Aug 3, 2019
    Messages:
    550
    Location:
    West Somerset
    Ratings:
    +1,065
    I have an old electric prop. but long since lost its instructions/details. It doesn't have a temp. adjustment and I've never known it get too hot.
    As I have to use it in the utility room - chilly and north facing - I sit it on panels of polystyrene to keep the base heat in. I use a couple of layers of Capillary matting inside and place the cells/pots on that. The lid has 2 vents which I leave closed when I first put the seeds in and then partly open after a day or 2. Germination for most things is pretty good.
     
  3. pete

    pete Growing a bit of this and a bit of that....

    Joined:
    Jan 9, 2005
    Messages:
    53,313
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Mid Kent
    Ratings:
    +100,931
    I've never used one without a thermostat, how hot is too hot?
     
  4. Pete8

    Pete8 Super Gardener

    Joined:
    Aug 29, 2017
    Messages:
    709
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Billericay, Essex
    Ratings:
    +1,747
    Mine is in an unheated greenhouse and I agree it can get very hot inside my heated propagator with thermostat set to 22c.
    The sun is now quite strong and when it's out temps can easily exceed 30c inside.
    The only solution is to remove the top for a while and replace it before sunset.

    When I worked, if it looked like a sunny day ahead, I'd remove one of the top panels and put it back when I got home from work - if I remembered...

    I have 2" sand in the base of mine which acts as a storage heater so on a chilly night the temps are easily maintained.
     
    • Agree Agree x 2
    • pete

      pete Growing a bit of this and a bit of that....

      Joined:
      Jan 9, 2005
      Messages:
      53,313
      Gender:
      Male
      Occupation:
      Retired
      Location:
      Mid Kent
      Ratings:
      +100,931
      If it doesn't have a thermostat maybe a cheap timer, hour on and hour off, but it would need to be in the shade.
       
      • Agree Agree x 1
      • ricky101

        ricky101 Total Gardener

        Joined:
        Jun 15, 2016
        Messages:
        3,567
        Gender:
        Male
        Location:
        Sheffield
        Ratings:
        +4,484
        Agee with @Pete8 if you put the prop on a sunny windowsill or in the greenhouse the temperature easily gets over 30c.
        A themostat will only cut the heating off, not the sunlight.
        Probably a cheap time switch as @pete suggests to cut the heat during daylight.

        Better to put it in good light but not direct sunlight and also , if fitted as most have, open its ventilator or raise the whole cover when you know its going to be sunny.

        Also good to place a layer of polysyrene or similar under the whole unit so all the heat goes up into the compost.
         
      • cactus_girl

        cactus_girl Total Gardener

        Joined:
        Mar 15, 2024
        Messages:
        1,070
        Gender:
        Female
        Occupation:
        Retired
        Location:
        Sutton Coldfield
        Ratings:
        +4,564
        I have a Ward propagator and never noticed it get too hot. There is no thermostat, but it does have 2 vents you can open at the top. But I only use it for say tropical seeds that may need extra heat. I never put it in the sun.

        I find a sunny window sill is just right for most seeds.

        I tried to hatch some eggs in it once, but nothing happened!
         
      • Purple Streaks

        Purple Streaks Gardener

        Joined:
        Aug 13, 2012
        Messages:
        599
        Location:
        Sconthorpe
        Ratings:
        +873
        Thank you so much ive found out where ive gone wrong . its on metal benching in the dwarf style green house and direct sun. i wonder if i put it under the staging where it doesnt get the sun would work ???? it would still get light but would have to relie on the heat from the propergator what do you think ?
         
      • NigelJ

        NigelJ Total Gardener

        Joined:
        Jan 31, 2012
        Messages:
        7,664
        Gender:
        Male
        Occupation:
        Mad Scientist
        Location:
        Paignton Devon
        Ratings:
        +25,373
        Wouldn't they need to be at chicken temperature, or a particularly sunny could have cooked them.
         
        • Funny Funny x 1
        • NigelJ

          NigelJ Total Gardener

          Joined:
          Jan 31, 2012
          Messages:
          7,664
          Gender:
          Male
          Occupation:
          Mad Scientist
          Location:
          Paignton Devon
          Ratings:
          +25,373
          In the greenhouse some seeds I germinate in a propagtor under the bench at the shady end, but even then I have one or two layers of fleece over the top. This gets used for slow germinating seeds that don't need extra heat.
          Seeds that need a bit of warmth are on a thermostatted tray in the garage with polystyrene under the tray. I use grow lights on a timer to give them sufficient light and the whole enclosure is painted white.
           
        • Pete8

          Pete8 Super Gardener

          Joined:
          Aug 29, 2017
          Messages:
          709
          Gender:
          Male
          Occupation:
          Retired
          Location:
          Billericay, Essex
          Ratings:
          +1,747
          As long as there's good light under the staging it should be fine.
          Seedlings need good light to grow without getting leggy.
          Too much heat and insufficient light will cause spindly seedlings.
          Good airflow is important too to deter fungi.

          You're relying solely on heat from the propagator at present during the night, so if that keeps the temps right then it should be fine in the day too.
           
        • Busy-Lizzie

          Busy-Lizzie Total Gardener

          Joined:
          Mar 13, 2024
          Messages:
          1,677
          Gender:
          Female
          Occupation:
          Retired
          Location:
          Norfolk and Dordogne, France
          Ratings:
          +5,994
          It shouldn't be in direct sunlight. Just needs light.
           
        • Philippa

          Philippa Gardener

          Joined:
          Aug 3, 2019
          Messages:
          550
          Location:
          West Somerset
          Ratings:
          +1,065
          If you are using an electric propagator early in the season ( Nov to March let's say ) then you really only need to site it in good light to ensure germination dependant on what seeds..
          If you are using the same in a GH, then you obviously need to take account of the temps during that same period. Fleeced in cold weather and possibly shaded if the sun comes out for long enough.
          After that, most will probably succeed in a warm spot indoors or in the GH. Obviously depends on what you are sowing, your location and weather tho.
          @cactus_girl I guess you may be talking about Chicken eggs but I can confirm you need a constant 30 C for Tortoise eggs to hatch successfully :biggrin:
           
          • Informative Informative x 1
          • cactus_girl

            cactus_girl Total Gardener

            Joined:
            Mar 15, 2024
            Messages:
            1,070
            Gender:
            Female
            Occupation:
            Retired
            Location:
            Sutton Coldfield
            Ratings:
            +4,564
            What a lovely thing to do - hatch some tortoise! I'll have to put my thermo in to see what they temp actually is.
             
            • Like Like x 1
            • Purple Streaks

              Purple Streaks Gardener

              Joined:
              Aug 13, 2012
              Messages:
              599
              Location:
              Sconthorpe
              Ratings:
              +873
              To water the seeds I have usually sprayed but am I better in using a watering can .
              Which method do you find best ?

              I have decided that I will paint a cardboard box white and put this around the seed under the staging. Also with my greenhouses being dwarfs eventually I will paint the brickwork white too.see it this works.
               
              Last edited: Mar 17, 2025
            Loading...

            Share This Page

            1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
              By continuing to use this site, you are consenting to our use of cookies.
              Dismiss Notice