With the following tips, you can learn how to take care of a cactus indoors and ensure sure your cacti are nice and healthy. Once you know these tips, taking care of cacti is easy for beginners!
Cacti are low maintenance plants that store water in their stems. They are found in hot, arid climates, like deserts, and therefore have adaptations to tolerate long periods of drought and minimize water loss. These features include a waxy outer coating and spines. Unlike normal leaves, cactus spines do not lose water through evaporation and protect the cactus from other predators.
When learning how to take care of a cactus, it is important to remember that they are native to the desert. Therefore, they enjoy warm, dry climates with infrequent watering.
How to take care of a cactus:
1. Sunlight
Cacti thrive in high-light conditions.
To make sure your cacti gets the light it needs, place it near a window that gets nice, bright light. The window should be able to provide at least 6 hours of bright light for your plant to grow. Rotate your plant periodically so all sides receive sunlight equally and to prevent unequal growth. Ideally, you want to place your cacti in a south-facing window, as these receive the most light. Avoid dark corners that do not receive any sunlight.
If you find that your cacti are not getting enough light despite being in front of a window, or you want to keep them somewhere in your house that does not receive light, consider getting a grow lamp. This way, you can be sure your cactus is getting the light it needs wherever you decide to keep it. I use a grow lamp indoors for my cacti and they seem to love it!
Signs your cacti is not getting enough light
If you notice the top growth of your cactus is becoming smaller and skinnier than the rest of the body, your plant is trying to “stretch out” for more sun. If you notice this is the case, transition your cactus to an area with more light. Unfortunately, this new, skinnier growth will be permanent and cannot fatten out. If you do not like how it looks, cut it off with a pair of clean garden shears. The cactus will be able to regrow and look “normal” if it is moved to an area with more light.
Signs your cacti received too much light
However, do not move your cacti directly from a shaded area to a bright sunny area. Even though cacti are desert plants, they can sunburn if exposed to bright light too quickly. Place the cacti in a shaded area first and slowly move it into sunlight over a week.
If your cactus is sunburned, the sunburned area will look brown and calloused, especially on the side facing the window. Unfortunately, once a cacti is sunburned, the area will not go away, so it is best to avoid sunburn in the first place by gradually exposing the cactus to increasing sun.
2. Water
Watering cacti can be tricky since overwatering cacti can lead to rot.
It is important to remember cacti do not need as much water as normal houseplants.
In general, cacti planted indoors can be watered about once a month. If your cactus is planted outdoors and you are in a hot, dry climate, it will need to be watered more frequently (around once a week). Before watering, check the moisture in the top inch of soil. If you notice the soil is still wet, do not water and check again in a few days.
If your cactus is in a pot, pour water until you see it begin to seep out of the drainage hole.
Do not water your cacti every day, because it can kill them.
Signs of overwatering in cacti
Signs that your cactus is receiving too much water include: becoming less stable, browning or blackening at the base, or a droopier shape. Your cactus might also feel mushy when you poke it. If you notice any of these signs, carefully remove the cactus and examine it’s roots- if you see any brown or black areas, it is rotting.
Signs of underwatering in cacti
While not as common, it is possible to underwater a cacti. If you notice your cactus showing brown markings on the edge, turning brittle, or puckering up, your cactus might not be receiving enough water. Slowly increase the frequency of waterings.
3. Keep a warm temperature
Since cacti are native to the desert, it is natural that they enjoy warm, dry temperatures. Cacti like temperatures of about 70 – 90 °F (21 – 32 °C) in the summer and around 50 – 55 °F (10 – 13 °C) in winter months. Do not leave cacti in temperatures colder than that because they could get frostbite.
Avoid keeping cacti in rooms that can get humid (such as bathrooms) as that can lead to rot.
Pay careful attention to the temperature when deciding how much to water. Hot, dry climates will require more frequent watering (about twice a month) compared to colder climates (about once a month).
4. Best soils and pots for succulents
The best types of pots for cacti are plain terracotta pots with drainage holes. These work best because they do not retain extra water – cacti hate staying wet for too long. These pots help the soil dry out faster and are much more forgiving if you water too often.
I recommend staying away from glass containers, and not planting cacti in terrariums when starting out because these can retain moisture for a long time. Once you have a better idea of a good watering schedule that works for your cacti, you can try these out, but in the beginning, terracotta work great!
It is important for cacti to be planted in a well draining, porous soil that does not retain water. Typical gardening soil for houseplants usually retains too much moisture for cacti and should not be used. I use a 70:30 ratio of succulent soil to perlite and find that that works best.
How often should you repot your cactus?
I recommend repotting every 3 years. Cacti can be repotted less often than other houseplants because they are slow growing and prefer being pot-bound.
The best time to repot is during the spring or summer time. Do not choose a very large pot because you could drown the roots. As always, choose a well-draining and porous soil.
After repotting, do not water for another week to allow the roots to settle in. If you water right after repotting, the roots are more prone to overwatering and you run the risk of rot.
5. Fertilizer
Cacti usually need little fertilizer. I tend to water with a succulent fertilizer once every 2 months and find this is enough to keep them healthy.
6. How to take care of a cactus: What if my cactus gets scale?
Scale are small, round, brown bugs that are indoor houseplant pests. They suck on the liquids and nutrients in cacti. It can take several tries to completely cure your plants of this pest.
The good news about scale? They spread slowly: therefore the damage to your plant will also be slow, giving you more time to tackle the pests.
Once you notice scale:
First, quarantine whatever plants have scale, so the infestation does not spread further. Scale does not move, so you can scrape it off gently with a knife or card.
Also, take a q-tip, soak it in rubbing alcohol and dab it at any bugs you see. This does not harm your cactus and helps get rid of any infestation. If rubbing alcohol is not enough, diluted neem oil also works well to treat infestation. You will need to do this once a week for several weeks until you no longer see any bugs.
Regularly inspect your cactus for scale, since catching these pests early makes treatment much easier.
The most important part of learning how to take care of a cactus indoors or outdoors: have fun!
Do not get discouraged if your first few tries at growing cacti are unsuccessful.
These are my tips on how to take care of a cactus indoors or out and how to fix common mistakes beginners make when growing cacti.
By following these tips, you can get a better idea of how to take care of cacti and maintain happy and healthy plants.
Do you have succulents too? Check out this article to learn how to care for them:
Every guide here comes from things I've actually tried on my own plants. Got a plant doing something weird? Send me a photo — I answer every one.
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