Should I water my Cactus in winter?

The simple answer is NO, you shouldn’t be watering your cactus over winter and here are the reasons why:

As the nights become darker your cactus will naturally want to go into a period of dormancy as it simply won’t be getting enough light to enable it to grow properly. Combine the darker nights with cooler temperatures and you definitely don’t want to water your cactus. Wet roots and cold conditions will lead to your cactus getting root rot and sadly this is pretty much always terminal. I keep my warmer climate cactus on my bedroom windowsill all year round. They sit just above a radiator but I still withhold water in the winter. A second reason you should not water your cactus in the winter is because this could cause them to become confused and want to grow, this will cause what we call etiolation. A plant is becoming or has become etiolated is when the new growth at the top is a lot lighter than the rest of the growth of the plant. Over time this will become thin and spindly and make the plant look distorted and just wrong. Once this has occurred there is no going back even if the lighting and watering problems are rectified this will still leave a mark on the cactus to tell its story long into the future.

If you keep your cactus in a greenhouse or an unheated conservatory you especially shouldn’t water. They will be more likely to survive the cold months if the soil is 100% dry. I keep all of my cactus and succulents (with the exception of a few) in my greenhouse which is heated to 6°C over winter.

As a rule of thumb for the UK we recommend to stop watering in September. This can be hard as we have had some really hot and sunny autumns just lately but if your plants are not in a centrally heated home I recommend not to be tempted to give them too much, if any water after September. Start watering again around April but again if we have any more cold weather predicted you may want to reconsider waiting a little longer.

To put this advice into perspective, your cactus or succulents, if healthy, will absolutely survive a little longer without water. That is what they have evolved to do. It will not however survive being wet or cold.

When you do water in April, wake your plant up gently with a light water to allow the roots to adjust from being totally dry to knowing to expect some moisture. Cactus are incredible and they can develop tiny roots really quickly to take advantage of a sudden rain shower to enable them to take up any water given before it evaporates from the soil.

Two final points on watering is firstly, never spray your cactus with water. They are adapted to survive in an arid (dry) climate and a regular spray or misting will only cause them to rot.

When you do water your cactus and succulents during the growing season (April to September). Give them a good water so that all of the soil is wet (make sure you are using the correct soil mix for your cactus and succulents and the correct size pot for the root system) and then wait for the soil to dry out before watering again. This could be 1 week or it could be 2 depending on the weather or the growth cycle of the plant. If you are not sure you are better to wait than over water. Never let your cactus sit in a pot with water in the bottom for longer than 2 hours.

NB: These answers are based on the reader being based in the UK