Do Indoor Cacti Go Dormant? Mine Do!

Welcome, I’m so happy to have you here!

To answer your question…

Yes, indoor cacti can go dormant during those cold winter months.

At least mine do.

Yours could too but just like everything in the world of cactus growing, it depends on your individual growing conditions.

Don’t worry, I won’t leave you wondering..

I’m about to walk you through the conditions needed for dormancy and how to tell if your plant babies are actually in hibernation or not.

I also think there’s a more important question we should be asking and that is, ‘Should indoor cacti go dormant?

I’ll share my thoughts on that but first, let’s dive into what you came here for;

What causes indoor cacti to go dormant?

Cacti are light-sensitive guys and gals that convert light into energy by way of the process of photosynthesis. It’s this energy they use to grow.

I don’t remember a lot from school, but that’s one thing that I do remember!

If you usually grow cacti in a bright window, they’ll notice the days getting shorter even though the temperature in your house is roughly the same all year round.

This will send a signal to your plant that’s it time to begin slowing down.

12 potted cacti growing in my windowsill overlooking my garden
Some of my cacti collection growing in my (usually) suny window.

Now is the perfect time to reduce watering (we’ll be looking at how to trigger dormancy in just a second).

The problem comes if your plants’ growth slows down due to reduced daylight, yet you keep watering.

With the soil wet, your cactus will keep taking nutrients from the soil and will grow long and thin (etiolation) in a desperate attempt to seek out light.

We don’t want this.

Also, The water in the pot will sit around longer which will likely cause root rot.

‘But what if I use grow lights?’

Great question, and this does change things dramatically.

If you keep the lights on the same level all year round, in your nice warm house, and keep up your usual watering schedule then no, your plants won’t go into dormancy and you’ll be able to continue growing all year round.

Should indoor cacti go dormant?

In their natural habitat, these amazing, resilient plants shut down during the winter months to protect themselves from frost and harsh conditions.

Essentially, they have a rest and prepare to begin the next phase of growth when the warmer weather comes around at the beginning of spring.

In our home, cacti have to deal with a reduced amount of light, reduced airflow, and higher humidity so they have to work a lot harder to survive, let alone thrive!

With this in mind, I believe that we should allow our plants the same opportunity for a rest when grown indoors.

That said, it won’t hurt your cacti to keep them growing with lights and it is a personal preference.

How to know

When your plant begins to shut down, you won’t see any new growth in the way of spines, pads, or blooms until the warmer weather comes around.

I like to use my bunny ears as a guide. This thing always seems to be growing!

I start looking for signs of slowing down around mid september here in the northern hemisphere.

When you stop watering, some of your plants may start to droop, wilt, or shrink slightly due to lack of water like my Eve’s Needle that you can see below;

My droopy and slightly wilted eves needle after two months of no water
My droopy and slightly wilted Eves needle two months into dormancy.

The temptation to water is almost too much!

How to trigger dormancy

I have a habit of overthinking just about everything so I like to try to keep this simple;

Here are my best tips for you;

First, stop watering at the end of end of summer/beginning of autumn.

I don’t water again after October 1st here in the northern hemisphere.

If possible, move your plants to a cool, dry place where they can live until the end of March/beginning of April.

I still like to provide mine with a lot of bright light during this time albeit with reduced hours due to the shorter days.

I keep mine in my conservatory which you can see below;

A picture of the inside of my conservatory with some potted cacti on the left hadn side
I’ve moved some of my cacti from the living room window into my conservatory ready for winter
a chest of drawers in my conservatory, with the potted cacti from my living room

I have heard professional growers remove light throughout this period altogether and keep plants in a dark garage or basement.

They will then slowly introduce light as spring rolls around.

I also keep the windows open as much as possible as good airflow is a key to healthy plants.

The minimum temperature range will vary on the type of cactus you have and I recommend researching their individual needs.

As a general rule of thumb, I keep mine between 5 to 10 degrees and keep it at that with an electric heater.

During this time, it’s important to carry out regular checks to see how they’re doing.

Only the other day I found mealybugs.. ugghh!

There are some exceptions…

Everything we’ve covered above applies to mainly desert cacti.

Forest cacti (Epiphyllum) such as the orchid and Christmas cactus come to life and bloom during this period.

Due to the reduced light, you’ll need to reduce your watering frequency to avoid root rot during these months.

Over To You

Are you ready for the winter now and where will you be keeping your plants during these colder months?

Let me know your plan or any questions you have in the comments section below and I’ll get back to you as soon as I possibly can!

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