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Planting tomato seeds in a propagator inside the house

Good morning!

I recently bought some small tomato plants from Homebase, however, they were looking a little poorly so I bought some tomato seeds this week to see if I can grow some for the first time, just in case the others don’t flourish.

I bought a propagator (just a plastic tray which comes with a clear lid), have planted the seeds, and have put them near the garden door (I don’t have a greenhouse).

My question is - are they ok inside the house? Or can i put them outside as they are in a propagator? 

Also, there is a bit on the lid I can open and close to  allow air in - I have kept it open a bit as I’m unsure how to regulate the temperature - will it get too hot if I close it?

Any tips would be very much appreciated!
Thank you



  • sabeehasabeeha Posts: 344

  • FairygirlFairygirl Posts: 54,353
    Keep them inside, on a windowsill with good light, until they've germinated, then remove the lid. If you get some coming on quicker than others, you can open the vent a bit instead. Small seedlings can get too damp/hot and die off if they're not getting some good airflow. 
    Once they have a proper set of leaves - not just seed leaves - you can prick them out, and pot them up separately into small pots. You'll need to keep turning them so that they don't get lopsided. Don't overwater them either. 
    They'll need to stay indoors until temps are suitable for going outside. You'll probably need to pot them on again before that  :)

    There are several threads about tomatoes, so you might find using the search facility at the top of the page could be useful.  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • sabeehasabeeha Posts: 344
    Thank you @Fairygirl

    Will their current place - at the bottom of a double glazed back door be ok? None of our window sills have enough of a ledge on them to hold the large tray - the kitchen one is particularly narrow! If they are no good on the floor, would being on the kitchen worktop near the door be suitable?

    Thank you for the tips! To be honest I did search “tomato seeds propagator” but couldn’t come up trumps for my situation (non heated propagator, no windowsill!)

  • Allotment BoyAllotment Boy Posts: 6,548
    The problem with being by a door is every time you open it  they will get a blast of cold air. If it's say a patio door that you don't need to use for now, then it will be OK, but floor level will always be cooler than up on a window cill. Tomatoes need a consistent 18-22 C to germinate well, once they start to grow they, can be in a lower temperature. 
    AB Still learning

  • FairygirlFairygirl Posts: 54,353
    It might be ok by the door. What they need more than anything is light. You'd just have to experiment.  :)
    I don't use propagators for seeds, mainly for that reason, although you can buy small ones which are designed for windows.  I find small pots easier, 3 seeds to a pot, and I just keep them sitting in little plastic pots that yogurt etc comes in, or in the plastic trays I get meat/chicken in, so that they fit. Easier for separating the seedlings too. Might be worth sowing a few more in a similar way just in case  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • Nanny BeachNanny Beach Posts: 8,669
    Top advice from Fairy. I wouldn't waste money on a heated propagator. Have you filled the tray? For this reason,I use quarter trays, they fit on Window sills, for small seeds. Larger seeds, window sill planters,lids small sections for individual seeds or tiny plants
  • sabeehasabeeha Posts: 344
    Thank you @Allotment Boy @Fairygirl @Nanny Beach

    I never thought of smaller trays or little pots etc. I just saw the propagator in Homebase and thought it looked useful! I thought the seeds had to be covered as I didn’t have a greenhouse. @Nanny Beach it wasn’t a heated one, just a glorified seed tray with a lid :)

    I need to think of the spot - maybe get a stool to make it higher… a warmer place would probably be my bedroom window!
  • FairygirlFairygirl Posts: 54,353
    edited April 2022
    That was my worry too @Allotment Boy, re the door.
    If your bedroom sill is better, then that's probably a better idea  :)

    I keep little plastic covers from small pots of stuff too - yogurts or sauces that my daughter gets. That's what I cover the 3 inch pots with. If I use a meat tray for sowing, I use the same trays to cover. 
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • sabeehasabeeha Posts: 344
    Thank you for the tips @Fairygirl - not having done this before, I have always thought you needed all the ‘stuff’ - happy to know that its not always the case.
  • ButtercupdaysButtercupdays Posts: 4,497
    I'm lucky as I have lovely wide windowsills, but with a lot of dahlias and seeds to bring on they are still not big enough. I have one large tray sitting on an old tv base behind the dahlias (the windowsill is at floor level, it's an old house!) and my big heated propagator is on a spare side table in front of my bedroom window, with more plants on the windowsill.  The greenhouse is getting full already!
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