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Indoors or in greenhouse

Hi folks

I've made a decision, have decided to simply put all of my freshly planted seeds and indoor started seedlings into my wee lean too greenhouse.  I'm interested to see how they cope.  Was using windowsills but most of them are above radiators and the best most optimum one has too much sunshine and a radiator and tbh I just want to keep things as simple as possible (despite the fact that I've loads of veg and flower seeds that I want to plant  :D)

And at nighttime the windowsills get very cold so my thinking is  .... there can't be too much difference in the temperature ??? 

I guess I'm just wondering if anyone else has tried this and what were their successes and failures (if any ....).

I should add that I am planning to keep basil, peppers and coriander indoors on a windowsill in the kitchen (which can get quite cold too).

Interested in thoughts.

Love hearing your views and advice :-) 


  • CatDouchCatDouch Posts: 483

    I was very interested to read your question as I have just had a new greenhouse assembled and want to use it for all of my seedlings.  I’m also a fairly novice gardener and always feel like I’m not sure what I’m doing!!

    Last year I had loads of pots with seeds in dotted around the house on windowsills and most of them grew too quickly and got very leggy.  So about 9 days ago I planted tomatoes, chives, basil and cosmos, all from seeds and put them in my new greenhouse, which isn’t heated although I did light my new paraffin heater one night. I was very excited this morning to see that the cosmos have started to come through so hopefully the others will too.  

    I’m not sure if that helps you at all but hopefully in another couple of weeks the rest will be growing too.  The minimum temperature at night got down to about 1 Degree C and the maximum in the day has been about 20 degrees, I’m in South Devon.

    Good luck with your seeds 😁
    South Devon 
  • @CDouch
    Hey thanks for posting.  Yeah I was using a windowsill as well and leggy seedlings 🌱 resulting.  Couldn't believe how quick they germinated and then started to wonder if that was right so early in the year. 

    Most of mine are now in my wee lean to so fingers 🤞 

    Be interesting to see .... 👀 
  • FairygirlFairygirl Posts: 54,860
    It really depends on the seeds/plants, and your conditions. Seeds of hardy plants will generally cope better. Half hardy ones may not have enough warmth, so it's a mistake to put them out too soon unless you want to heat the greenhouse. 
    An unheated greenhouse can be very, very cold overnight - much colder than a windowsill in a house, for obvious reasons. For example, it's only in the last week or so that mine has been above the outside temperature through later evening, and that's mainly because there's been enough warmth during the day to make the greenhouse much warmer to start with. It also means the temps in it rise a bit more rapidly in the morning. Overnight, it's probably much the same as outside, so when it's below zero outdoors, the greenhouse is the same. That fluctuation in temps can also be a problem. 
    It's important to close greenhouses up early enough at night too - it's very easy to retain cold, just as it is to retain warmth. 
    It's why sowing too early is often not worthwhile, and means unnecessary expense if you're using any kind of fuel to heat a greenhouse instead of waiting a few weeks. Many seeds just need to be sown a little later, and will catch up with those sown early and given extra heat to get them to that stage.
    It's where you put everything as it grows, and gets pricked out that's always the main problem though.  Sowing a little later helps with that  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • AnniDAnniD Posts: 12,468
    I'd advise keeping a very close eye on the forecast, and if it shows any signs of frost or around freezing, you might want to consider moving them back indoors. At this time of the year it can be a real hit and miss situation.  I have a full size greenhouse and the temperature can vary from night to night, even though the day time temperatures are pretty much the same.
    If you can afford to lose the seedlings and can re sow, then if you feel it's worth taking the risk, by all means go for it.
    I would also advise investing in some fleece as that would definitely help with keeping any warmth over the seedlings. 
    As in all things garden related, it can be a gamble.
    Good luck  :)
  • @Fairygirl
    Yeah I realise that I started some of the wee seedlings off too soon, although I did go ahead and repotted the  sweetpea and broccoli seedlings, trimmed and buried deeper accordingly whether correct or not ... time will tell.  Will go ahead and wait until beginning of April before I plant anymore and see what happens if I place them in my greenhouse 😀

    Thanks again 
  • @AnniD

  • tui34tui34 Posts: 3,442
    If your greenhouse has a clear roof then the seeds are better off in there - then there's a question of warmth at night.  You could bring them in at night into a dark but warm room.
    A good hoeing is worth two waterings.

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