How Cold Does it Have to Be Before You Bring Your Plants Inside?

An inevitable part of being a plant parent (and living in an area that actually gets cold in fall and winter) is figuring out what to do with all your outdoor plants—and even keeping your indoor houseplants alive—when the temperature starts to drop.

If you’re wondering at what temperature threshold you should be bringing your plants—at least, the ones you can move—inside, there’s a short answer: when nighttime temperatures reach 45 degrees (F), it’s time. According to the Department of Plant and Soil Science at the University of Vermont, most tropical plants will suffer damage if temperatures drop below 40. But there’s a little more to it than just toting your green friends indoors.

Before you bring your outdoor plants inside, make sure that they’re healthy and insect-free. Pests and plant diseases spread much quicker and easier indoors than they do outside, so treat your plants accordingly. This means you may have to prune, repot and replant them. To get insects out of your plants, try soaking the pot in a tub of lukewarm water for about 15 minutes—it should force them out of the soil.

It’s also a good idea to gradually acclimate your plants to indoor light and temps —moving them from the bright, airy outdoors to a stuffy, dimly lit part of your home could shock them. For a few days, bring them in at night and then back outdoors during the day. If you can, shorten their time outdoors by a few hours every day until they’re indoors full time.

Make sure you clear an area in your home for them that gets plenty of sunlight in order for them to stay healthy and happy. Give your windows a good cleaning for to let the best quality sun in.

And if you have outdoor plants that have already been struggling, it might be time to let go—if they’re already having problems outdoors, it’s only going to get worse indoors.