Cactus is a tough hardy plant that can even survive the ministrations of a brown thumb gardener.
But about 90% of cactus problems and ultimately death are linked to improper watering. This brings us to today’s article: how often to water cactus indoors.
Considering that cacti are famous for being low-maintenance, easy-going plants perfect for newbies to cut their indoor houseplant gardening teeth, this is surprising.
Putting the above grim stats in context, if you can perfect the art of watering your indoor cactus, you’ve practically nailed done the heavy lifting in terms of care and maintenance.
You’d have literally zero chance of losing your cactus.
The article covers everything you need to know including how much water indoor cactus needs, when to water the plants, and how to water them.
How Often to Water Cactus Indoors
If there is a slugfest of neglect-tolerant houseplants, cactus would likely get the crown in the watering category.
With origins in arid environments, these succulents thrive on drought-like conditions, producing roots that grow downwards in a relentless pursuit of available moisture in the soil.
And since their ‘super powers’ include the ability to store excess water in their stems and leaves, they can thrive comfortably while the roots seek out water or while waiting for the rains to fall again.
When talking about how often to water indoor cactus, the general instructions are pretty straightforward. Water your indoor cactus when the soil is bone dry or at least over 90% dry; or not more than once a week.
But it is quite easy to get it wrong because so many other factors come into play. These watering variables are the reason most people new to growing cactus have to deal with incidences of cactus fatality.
So how often you water your indoor cactus is dependent on factors like
- The time or season
- Prevailing weather conditions
- The size of the pot
- Location of your cactus
- Soil type
We would look at how all those factors impact how much water you feed your cactus. We would also discuss the best ways to water indoor cacti and the type of water that is best for them.
Factors Affecting How Often to Water Cactus Indoors
As stated earlier, several factors affect the frequency of watering indoor cacti.
Though the indoor cactus watering mastery curve might seem steep, it is actually easy to get the hang of it.
Below are some of the conditions that affect your indoor cactus irrigation schedule:
How weather affects the frequency of watering indoor cactus encompasses several factors like:
- Temperature/humidity levels
- How often to water cactus in summer and
- How often to water to cactus in winter
Generally, like most succulents, cacti should be watered more often in the warmer summer months because this is their active growing season.
They use up more water to process energy and perform other activities related to growth.
Besides, the rate of loss of soil moisture through evaporation would be higher at this time.
In the growing season when temperatures are higher, the soil should be soaked deeply during watering.
Watering cactus in winter needs to take into consideration the fact that the plant is hibernating or resting.
It usually needs just enough water occasionally. The soil doesn’t dry as fast compared to the growing season.
So the period between watering sessions is usually longer.
However, no matter the prevailing weather conditions and whether in summer or winter, the soil must be bone dry before watering again.
Locations of pot or planter
When talking about location, it is almost impossible to avoid an indoor cactus watering vs. outdoor cactus watering comparison.
Essentially, cactus grown indoors have lesser water requirements than cactus grown outdoors mainly due to the latter’s exposure to outdoor weather conditions.
But even indoors, cactus water requirements are also location-dependent.
For instance, pots place close to windows and exposed to bright light would need relatively more watering because they lose soil moisture faster.
Expect the watering frequency to go up a few notches if the location is also windy or drafty.
You are also likely to water your cactus more often when kept near ovens, furnaces, and heating vents.
As well as proper watering, the right potting soil ranks high as one of the most important growth variables when it comes to growing cactus.
Cactus generally need well-draining, loose soil to thrive. The best potting soil for indoor cactus must therefore come with those qualities.
Thing is, too much soil moisture can lead to root rot and other problems.
Loose, well-draining soil allow excess water to drain easily out of the pot. Loss of soil moisture in this type of soil perfectly matches the watering requirements of cactus.
On the other hand, compact or heavy soil retains too much water or moisture.
This is not ideal for your cactus; your options are either to repot the plant in a high-quality potting mix or mix in perlite or coarse sand to improve soil drainage.
Generally, if the soil is heavy or compact, you’d have to water your cactus less compared to well-draining soil.
Size of the pot and drainage holes
The presence or absence of drainage holes and how big or small the pot affect how often you have to water your cactus.
Ideally, no matter the size of the pot, you want one with at least one drainage hole at the bottom.
This ensures that the soil is never soggy creating the perfect environment for the roots to grow.
In terms of size, the basic rule is that cactus grown in bigger pots need more water than those growing in smaller pots.
Given similar weather conditions, the soil in smaller pots dries faster.
So if you grow cacti in differently-sized pots, you’d have to water the smaller pots more often.
Cactus species and size
There are different types of cacti in terms of both origin and size.
The combination of these two factors implies different water requirements.
Some would thrive better with consistent watering while others require infrequent watering to thrive at the same rate.
Generally, smaller cactus plants require less watering than larger cacti. Still on the subject of physical attributes, as it relates to watering, cacti with bigger and thicker leaves need water more often than cacti with thinner/smaller leaves.
Cactus plants of arid origins (thicker leaves) need less water than forest cacti.
Examples of these include the Prickly Pear cactus that require less watering than the Orchid or Christmas cactus
So it would be a good idea to know your cactus specie to correctly figure out its water needs.
How To Water Indoor Cactus
There isn’t a single ‘best’ method of watering indoor cacti. Most folks stick to a method that works best for them depending on factors such as the weather conditions.
One great indoor cactus watering method involves placing the pot on a drip tray or saucer filled with water and allowing the soil to soak the water from the bottom.
This method works best if the plant is grown in a terracotta pot with drainage holes.
The terracotta pot would clearly show the upward progress of the water. Remove the pot from the tray or saucer when the water is about midway up the soil.
The ‘drip’ method is another great way of watering indoor cactus.
This method employs a water hose set to the lowest level, allowing the water to slowly drip directly on the soil. Let the water percolate down the soil until excess begins to seep out the drainage holes.
Both methods are forms of deep watering used to thoroughly soak dry soil. Most succulents are watered this way. In both cases, allow at least a week before watering again.
However, the weekly watering frequency is heavily dependent on the conditions mentioned above.
The critical issue is to ensure that the soil is completely dry before watering again.
So you might want to invest in a moisture meter. This is an inexpensive tool you can get in most garden centers and online stores selling garden hardware and tools.
And the best part is, the tool is easy to use.
Only water your cactus when the meter indicates that the soil is completely free of moisture.
Growing cactus indoors is easy; requiring very little in terms of maintenance and care for a thriving, healthy plant.
The most crucial aspect of indoor cactus care is watering. Getting it wrong can be fatal.
The right way to water a cactus is linked to how often you water it.
This, in turn, depends on factors such as the weather conditions, the size of the pot, soil type, etc.
The rule of thumb, though, is to water your cactus only when the soil is bone dry.