House plant expert gives a top tip for keeping your indoor plants alive in an unheated conservatory

Wondering whether your indoor plants will survive a cold spell in an unheated conservatory or extension? Here's what plant experts have to say

Conservatory with house plants
(Image credit: Getty)

Protecting garden plants from frost and icy winds is one of the essential winter garden jobs if you're growing plants that aren't fully hardy. With indoor plants, everything is much simpler, because, well, you keep them indoors. Or is it? It's one thing if you've following one of the trendy indoor garden ideas and created one in a warm, steamy bathroom or a bright and well-heated living room. But what if your indoor plant display is grouped together in an unheated conservatory or small extension that doesn't have its own radiator? 

Growing indoor plants in a bright conservatory seems like a natural decision; the trouble is that some conservatories were built without any permanent heating solutions – and without taking into account the possibility of prolonged subzero temperatures we're currently experiencing. How will your house plants fare in a conservatory or orangery that is unheated, and where overnight temperatures can plummet during very cold spells? 

keeping plants indoors in winter

(Image credit: Haddonstone)

We have some very good news: it turns our that most tropical plants will survive in an unheated conservatory even if temperatures do fall to only a few degrees above zero in there. There is, however, a trick to keeping them well throughout the cold spell: stop watering them. 

While most tropical house plants typically like to be kept moist and even spritzed with water to maintain higher-than-average humidity levels, they will not be happy with cold and humid conditions. Don't let the roots dry out completely, but water very sparingly until temperatures go back up. 

If you're growing succulents or cacti, you don't need to worry about them at all, as these desert plants are used to temperature fluctuations, and very cold nighttime temperatures are not a problem for them. 

Indoor plant

(Image credit: Unsplash)

Remarkably, you can even grow citrus trees in unheated conservatories – you just need to make sure they get plenty of light and are frequently fed with citrus fertiliser. 

If you are worried about your tropical plants getting a little cold, Richard Cheshire and Richard Hull, plant experts from Patch, recommend grouping the plants together for warmth and away from draughts. They also stress the importance of maximising natural light: 'As the days are shorter, it's important to maximise sunlight, so moving them closer to the window is also beneficial.' 

So, keeping your plants alive in an unheated conservatory is actually much less daunting than it may seem: just don't overwater, ensure there's plenty of light, and let them huddle together for warmth. 

There's plenty more tips on caring for indoor plants in winter in our guide too.