Little Plant House Temperature for Overwintering

Can someone please tell me what temperature I should keep the heater set at in my little plant house in order to keep my potted perennials safe and healthy for the winter ?
Zone 6..Thank you.

What zone are your plants hardy to? If you've got tropical stuff then you probably ought to try and keep it at least at 55 or so for best results, but if you're just trying to winter over stuff that's not quite hardy in your area then you can get away with a lot less. If you can keep it above freezing you ought to be OK for anything but tropicals.

Just above freezing for perennials and well above that for tropicals, if you know the names of your tropical plants then either books or garden center labels should tell you what winter temp the tropicals need to stay healthy, in a small house trying to care for both will be a huge challenge due to space to separate the plants, too hot and perennials will grow throughout there winter heated house, but they will be weak and susceptible to mould and diseases, it is also very important to ventilate the greenhouse even in winter days, I do mine between say 12 to 2 o'clock in the day, when it is bright or sunny, also keep any snow off the roof etc to allow low winter light in, if no ventilation is done, then both the soil and any foliage will rot easily. good luck, enjoy your new house and just experiment for your own plants needs. WeeNel.

Thank you for this good information. I do not have any tropical plants and all of my perennials are hardy to my zone 6. Thing is they are all in patio pots and not in the ground which is why I thought they needed Winter protection. When I saw the condensation inside I realized I had better open a vent !! I sure hope all these little plants survive !

Hi Stormcloud, in your zone I dont really think you will need to add extra heat for perennials as they are used to going into winter dormancy, because they are in pots though, you are right to give them protection, the only time I would add heat was if you were getting prolonged FREEZES, then maybe, even just a light bulb to stop the plastic from freezing, I always open the vents on my large greenhouse, usually about lunch time as the temp will have risen enough even IF there is no sun to warm the greenhouse, try to keep your plants as dry as possible, only water IF the soil has dried out or you will add to your condensation problems, this condensation causes mould, fungus and diseases to get hold if you dont change the air inside the greenhouse, even just an hour a day will help the air flow, on a nice sunny day, open it for longer. all your plants need is protection from the really cold or frost, not heat as it will send them into growth and then it is harder to control the temp for the new tender foliage. just be vigilant and water only when really needed, Good Luck. WeeNel.

WeeNel, YOU are a life saver! I never thought about using a light bulb in my little greenhouse. Great idea! It sits on my porch in a sheltered location, but that will do the trick! WOOHOO!

You wecome Doc, hope it works for you, just always keep a check on any naked bulb just incase a bit of dried foliage lands on it and can start a fire, but you will be surprised that a light bulb can give off some heat, you dont want hot, just not freeze. Good Luck and happy growing. WeeNel.

Use a 15watt light bulb over the water pump to keep it unfrozen in the winter. It's boxed in with vents. But that would work in my baby greenhouse.

Now your talking Doc, go for it and give it a try, Very Best Wishes. WeeNel.

Thanks WeeNel...I have been following your advice and everything in my little plant house is looking just great...Now I have high hopes for Spring revival !