Depending on where you live in the world It may be that time of year again when you need to start overwintering your cacti & most of the succulents that you have in your collection.
When it comes to overwintering your prickly and succulent friends, then the biggest factor is to keep them cool and dry.This is important as this will discourage them to continue growing during the minimal daylight hours that is attributed to Winter, which will prevent stretched out etiolated growth.
The cool temperatures will encourage them to rest for the Winter, and then in the Spring they are more likely to produce flowers if they have had a Winter rest period.
Here is a video that I made on how to overwinter you cacti and succulents and also a video on how to overwinter your seedlings where I talk about this topic in a lot more detail but here is the video but please read for more information on what you could do.
A few exceptions when it comes to keeping them dry, is with the likes of the Autumn and Winter flowering cacti such as the Epiphytic cacti, e.g Rhipsalis and Schlumbergera cacti and some of the Winter growing succulents such as the Crassulas, and the Mesembs, e.g Lithops and Conophytums, so double check your plants individual needs but don’t assume that they all require no water over winter.
Some of the Epiphytes such as Schlumbergera (pictured above) and Rhipsalis are Winter flowering plants and do not like the soil medium to be kept totally dry for long periods.
All the Desert cacti and succulents appreciate a dry and cool room to overwinter in that ideally receives some sunshine during the day, but if the only position you have to overwinter them is a bright but sunless north facing window then they will not come to any harm as long as they can be placed back into a sunnier position again from Spring onwards when they come back into their active growth again.
Overwinter the Desert cacti and other succulents at an ideal temperature no lower than 5-7c (41-45f) but many growers have great success with overwintering their plants lower than this at 4c/39f but because I have no experience of overwintering them lower than 4c/39f I can’t recommend this from my own experience.
Melocacti, Uebelmannia, Discocacti and some other succulents are not as cold hardy as the Desert types and I would recommend overwintering them at no lower temperature than 12-15c. (53-60f)
Epiphytic cacti do not have a winter rest like the Desert types do, and ideally temperatures should not drop lower than 8-10c for these cacti during the Winter.Although these cacti can survive temperatures that are lower than this, their stems are prone to spotting and scarring in they are kept at too low of a temperature.
Cacti and succulent seedlings will need to be overwintered very differently during their first winter, and do not rest over the winter months like mature cacti and succulents do.
The different requirements with over wintering them all depends on whether you are growing them in a propagator with heat and grow lights or whether you are growing them in the baggies or without the baggies. Seedlings need to be kept warmer and also slightly moist over the Winter to stop the delicate root hairs from drying out, and it can be tricky trying to keep them moist without encouraging them to rot and to grow etiolated over the Winter if growing without special grow lamps.
Check out this video I have made where I explain in a lot more detail about How to overwinter your Cacti and succulent seedlings during their first year.