Question for fellow gardeners

I always have a lot of potted plants in my garden and on the patio. Every year I try to get them through the winter, but unfortunately with limited success. So I end up buying new ones every time.
Now I’d like to have a small shed built at the back of the garden where I can store the potted plants.
The ones I find are always greenhouses. Can I use these for my purposes without heating? The shed would be in a very sheltered spot, out of the wind.
Yours, Petra, who doesn’t know much about this...

Hi Petra,
A glass greenhouse isn’t suitable for this. It’s too cold.
I always put mine in the garage. It’s attached to the house and warmer.

Best regards, Marion

My mother-in-law keeps hers in a conservatory that isn’t heated very well. I also think a garden shed would be too cold. 

Yes, but there’s no room in the garage. And in the basement or the attic—that only works for small plants.
There has to be something out there that has walls and lets light in from above.

I keep some of my plants in the basement—if they need a rest period—or in the hallway. At least it’s protected from frost, and they get some light there, too. So far, they’ve all survived.

Dear Petra,

It really depends on which plants you want to overwinter. Some are more sensitive to the cold than others. And it also depends on the winter temperatures that are typical in your area.

Why don’t you start by making a list of which plants you have, how many need to be accommodated, and how big they are? Then I’d try to find the right spot for each one. That’s how I do it, anyway.

There are also heated greenhouses. But of course, they’re expensive to maintain. It’s definitely not worth it if you just want to overwinter your plants.

What if you wrap the plants themselves in winter-proof material even in an unheated greenhouse?
To do this, place the pots slightly elevated (e.g., on wood, Styrofoam, or bubble wrap) so they don’t touch the cold ground. Wrap a jute sack around the plant. Stuff dry leaves or straw between the plant and the jute sack for insulation.

Best regards and good luck with your planning—Ina

Ooh, I can already tell this won’t be easy. I could just buy new plants for the pots every year. But that’s not really what I want.
Maybe there’s a wooden shed with big windows so the plants still get enough light?? So many questions...

Dear Petra,
we have a greenhouse and a wooden pavilion with large windows. So I can compare them. If I had to overwinter plants, I would put them in the wooden pavilion. The reason is that my pavilion is better insulated than the greenhouse. The wooden walls are 4.5 cm thick, so it is nice and sturdy. Underneath, in the floor construction, we stuffed felted wool everywhere between the wooden floorboards as insulation. The floorboards also lie on extra stone tiles, so the cold from the ground would first have to work its way through the extra layer of stone, then through the felt, and then through the wooden floor. And the plants themselves are also in a pot, after all. 

There would also be enough light through the large windows. You could also install shutters on the outside or hang thick curtains in front of the windows from the inside if you wanted to minimize the light and also the cold that inevitably comes in through the window glass.

A greenhouse, on the other hand, has double walls made of plastic. That insulates against the cold from above and the sides. It stores heat in the hollow chambers of the plastic. But it is not insulated at the bottom, because there is soil there, or a few stone floor slabs on the path. The cold from below would simply always be there in winter.

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So from my point of view, the warmer option would be a pavilion. We had a power line put into ours because, of course, we wanted light. While we were at it, we had a branch installed as an outlet. So if I had plants there in winter, I could also switch on a fan heater for a while during a hard frost (under supervision, because of the wood).

In winter we were in there now and then, and I found the climate there very pleasantly dry. Cool, yes, but not as cold and damp (because of the soil) as in the greenhouse.

Maybe my tips will help you a little. Of course, you can also store other things in a pavilion. It wouldn’t be just for the plants. In any case, we really like ours.

Kind regards, Ina

P.S. I’m attaching a picture of ours during assembly. Here you can also clearly see the floor supports and the felt in between. Pavilions come in all sizes and wall thicknesses. We bought ours online from Gartenhaus GmbH.

Ina, wow… You really know your stuff. I think that’s the kind of pavilion I’ll go with. 

Dear Petra,

we also have a greenhouse in our garden. It’s quite large (so much so that a building permit was required) and has a really deep foundation. The greenhouse is heated in the winter, but it’s not spacious enough to accommodate everything, so many of our plants also overwinter in the stairwell and in the attic apartment.

The heater is a special greenhouse heater (portable and with a programmable fan), but it pays for itself when you weigh the purchase cost against the cost of constantly having to buy new plants ;-) In any case, the electricity costs stay within reason thanks to the fairly mild winters in the Ruhr region :-)