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Growing on

Hi all,

I generally grow from seed the cheap way: on a sunny indoor windowsill in a non-heated propagator (basically a seed tray with clear plastic lid).

Once they've germinated, is it best to just take the lid off and leave them indoors to grow on? (warm >20 degrees C, light, but not airy or humid).  Alternatively, should I put them in our unheated conservatory? (frost-free, but would be quite a drop in temperature).  I'm worried that there's no intermediate stage between germinating and hardening off in the conservatory e.g. a heated greenhouse.

Many thanks in advance,



  • Busy-LizzieBusy-Lizzie Posts: 14,536

    I would keep them indoors for a bit, so long as it's light enough or they will go spindly, especially as a very cold spell is forecast. Take the lid off, as you say, they can damp off if it's too humid under a lid.

    Dordogne and Norfolk
  • Also be careful with the conservatory in case it gets really hot during day like ours. We once put our seedlings out in a mild late winter/early spring and suddenly the day temperatures rose and with full sun during the day all our little seedlings dried out in one day and died.

  • You can get propagator lids that have a little vent in the centre, so that you can open it and reduce the humidity levels and allow some heat to escape. If yours aren't like this then you can just prop up one edge of the lid with a wedge of some sort.

    I usually do this and then move them to a windowsill for a bit longer, so that their leaves harden a little. This gives you that interim step between germination and the greenhouse and allows a more gradual process of hardening off.

    The greenhouse may well be warmer than the windowsill in the daytime, but cooler at night, but the air is also more humid, which helps them cope. I am blessed with wide and deep window sills large enough to hold a full size gravel tray and every spring almost all of them are full of trays of seedlings on a production line!

  • Thanks all for your advice image

    @Buttercupdays - I put the propagators on a south-facing windowsill, so they get a good amount of light.  You mention moving them as an interim step before hardening off.  So, I'm wondering, where do you put your propagators in the first place for germination - if not on a windowsill?

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