Lyn is a horticulturist and YouTuber with over 35 years of experience growing succulents and cacti.
Can Cacti and Succulents Survive the Winter?
Today let's talk about whether or not you need to bring your cacti and succulents inside for the winter. There are a few factors to consider:
- Plan according to the coldest average temperature for your area. Generally, cacti cannot withstand temperatures colder than 41 degrees Fahrenheit.
- Consider the humidity. Cacti and succulents like arid climates, the drier the better.
- Determine what type of cactus or succulent you have because some are much hardier and can survive winter temperatures better than others.
Whether or not your cactus will survive the winter depends very much on where you live in the world. If you live in a warm climate that's very arid and dry, doesn't receive much rainfall in winter, and doesn't get frost, then you can keep a lot of cacti and succulents outdoors. You can even grow them out in the garden.
However, if you're like me here in Ireland, our winters are very wet. They're cold. We often get frost and snow. I have to overwinter my cacti and succulents either indoors or in my greenhouse.
1. What Is the Coldest Temperature Cacti Can Withstand?
When it comes to minimum temperatures, for many varieties of cacti, the coldest temperature they can withstand is 41 degrees Fahrenheit (which is about 5 degrees Celsius).
However, that is only if they're kept totally dry with no water given to them at all from mid-September until late March. They'll only withstand cold temperatures if they are kept unwatered. If they're watered in cold temperatures, they will succumb to root rot.
2. How Does Humidity Impact Cacti and Succulents?
It is very important that humidity is not overlooked. The colder the temperature, the drier the air has to be. The combination of high humidity and very cold temperatures is a disaster for cacti and succulents. They will come down with mold, fungus, and other health issues.
Cacti and succulents have to be kept cool and dry—very arid. In my greenhouse, I have a dehumidifier that keeps the air at about 30% to 40% humidity. If I didn't, the humidity would be very high and my cacti wouldn't survive. That's why I overwinter them at 5 degrees C, which is 41 degrees Fahrenheit.
3. How to Overwinter Different Varieties of Cacti and Succulents
Some cacti need to be overwintered at a temperature of 10 degrees Celsius, which is 50 degrees Fahrenheit. These are the more tropical varieties of cacti, such as the Pilosocereus, the Brazilian types of cacti that need a mild climate to overwinter.
With some epiphytic cacti, they will also need to come indoors for the winter months. So if you're not quite sure what type of cactus you have, I advise bringing it inside to overwinter in your house just to be on the safe side. I only recommend watering during the winter if your home is centrally heated and the plants start to shrivel.
Best to Bring Inside
I hope you find this article useful and you now know what to do to protect your cacti and succulents through the winter. Remember, if in doubt, bring them inside for the winter. For more information about growing cacti and succulents, check out my other articles below. Have a fantastic plant-powered day!
Tips for Growing Cacti and Succulents
- How to Repot a Christmas Cactus and Thanksgiving Cactus
With a few simple tips, Christmas and Thanksgiving cacti are quite easy to repot.
- Do Cacti and Succulents Need Direct Sunlight?
Some cacti and succulents need plenty of sun, but some can fare quite well in indirect light. Find the best option for you and your home.
- How to Get Your Cactus to Flower
Having trouble getting your desert cactus to flower indoors? Make sure you aren't over-potting and remember to overwinter! These tips and more inside!
- How Cacti and Succulent Soil Is Different From Ordinary Potting Soil
What's the difference between regular potting soil and soil made for growing cacti and succulents? Does it even matter? Learn how to get the best results for all your plants, starting with soil!
- How to Make Cactus and Succulent Soil Mix
Learn how to make your own cactus and succulent potting mix using three simple ingredients—soil, grit, and horticultural sand.
© 2021 Lyn Kimberley