What is winter dormancy?

Most plants go into a period of winter dormancy. What this essentially means is the plants slow down, hibernate or ‘go to sleep’. They stop growing or slow down completely, and therefore stop taking up water from the soil as much as they would during Spring and Summer.

Houseplants during winter dormancy

This is particularly applicable to cacti and succulents and seen in most houseplants too. However, indoor conditions such as warmth can keep houseplants growing, you may just see slower/smaller growth.

With houseplants, it is a good idea to trim back this dormant growth in Spring so they can regrow bigger and better during the growing season. And of course, slow the watering right down too. It is good practice to only water most houseplants when the soil is dry, not before. Especially during winter.

Cacti & succulents

Why does winter dormancy happen?

In the wild, cacti & succulents live outside in varying conditions. They will experience sharp drops in temperature and rainfall during winter months and have evolved to cope.

The period of dormancy is especially important for their growth the following year, including their flower production if they are mature. It is a period of rest, to conserve their resources and is crucial for their strength the following year.

Not to mention the rot you may risk introducing if kept watered throughout winter.

When do cacti & succulents go into winter dormancy?

Usually around September time. When daylight starts to shorten, and temperatures start to drop. This usually lasts until around March, when the UK starts to warm up.

Should I bring them inside?

Yes, if they live outside they need to be protected from frost at all costs. Because there’s so much water in their stems, if this water freezes, the entire plant is dead in an instant. If you have the ability to bring it inside (if it isn’t already there), then do. Excess rain will also likely cause them to rot.

Alternatively a dry space like a greenhouse can work, as long as it is kept above 5 degrees celcius. See below for more information on temperatures.

What to do with watering?

You want to make sure to stop watering by the end of September at the latest. Some succulents are winter growing, see exceptions below. But overall, slow the watering right down in September so they can start to dry out.

Succulents may need a little water during the whole period, as they are faster growing than cacti. But this will only be a light sprinkling, not a full drenching like we do during Spring & Summer. Check if your plant looks particularly wrinkled, or is dropping lots of leaves, and of course if the soil is bone dry first before you do this.

Should I feed them?

No. Only light feeds are recommended for cacti & succulents during the height of the growing season. Feed can cause bloating and stretching, so only do so if your plant needs it during Summer.

What about temperatures?

Cooler temperatures are better, anywhere between 5-12 degrees celcius. They generally don’t want to go below 5 degrees for extended periods, and try to keep them away from hot radiators or open fires. Some species such as many Opuntia can go below 5 degrees if kept completely dry, so it is always advisable to research your particular species to be extra safe.

Do they still need light?

Yes, but nowhere near as much. So it’s fine to move them to a cooler, slightly darker room, as long as you keep them dry. Air flow is also very important – opening windows or having a fan on for a few hours a day can keep the humidity away and keep them happy.

Are there any exceptions?

Some species of the following plant families can carry on growing through winter, so you don’t need to worry too much about moving them or changing their temperature.

Just be super aware of their growth and follow the cardinal rule of cacti & succulents: only water when the soil is bone dry.

• Aloe
• Haworthia
• Gasteria
• Aeonium
• Schlumbergera
• Rhipsalis
• Epiphyllum
• Tylecodon

What else should I be aware of?

Basically, what we advise is to just leave them alone! No repotting, pruning or moving about is advised. Cacti & succulents are very resilient, but any plant can go into shock based on a variety of factors such as too much pruning, over watering, or sudden changes in environment. So it’s best to save all of this for the growing season when they are actively growing, so they can best respond to things we throw at them!

Coming out of winter dormancy

To bring plants safely out of winter dormancy, it is best to start slowly. Once we get to the warmer months, around March. Be sure the last frost has gone before moving plants back outside and try and introduce water slowly. If they are inside, move them back to a sunnier spot to give them extra light and warmth.

Give a small water first, and then gradually ramp this up, remembering to check the soil fully and only water again once the soil is bone dry.

You can then begin repotting and pruning to ensure your plants look the best and are rid of any old growth before bursting back into life!

As always, for any specific queries or problems, please do reach out to Hayley and the team at hello@mintplants.co.uk