How Often Should I Water My Cactus?

Whether you choose to grow your cactus outdoors in the ground or indoors in a pot, its health, appearance, and lifespan will depend on how and when you water it.

Unlike most green plants that require frequent watering, a cactus grows best when you water it only sporadically. If you accidentally overwater a growing cactus, you increase its chances of developing root rot, which could kill it.

Keep reading to learn how you need to water your cactus and what you can do if you accidentally overwater the plant.

How Often Should You Water an Indoor Cactus?

In general, all indoor and outdoor plants need water, fresh air, sunlight, and potting soil to grow and survive. However, the amount of water or the intensity of light will vary with every plant species.

Nearly 1750 different types of cactus plants together make up the plant family Cactaceae. Despite the vast variety in colors, sizes, qualities, or lifespans, nearly all cactus plants are sensitive to water and humidity.

Fortunately, cactuses are extremely easy to grow and are excellent houseplants for inexperienced plant caretakers. As long as the cactus plant’s basic needs are met, it can survive and retain its unique appearance for many decades.

Hence, if you have a cactus plant growing indoors or outdoors, follow the following watering routine to maintain its beauty and strengthen its immunity:

  • If you are growing your cactus indoors, pot it inside a well-draining soil mix, and if your cactus is planted outdoors, plant it next to other water-sensitive outdoor plants.
  • Before you water your cactus, check the amount of moisture in the soil.
  • The goal is to let the soil fully dry up all the way before you add any more water. You can use a moisture meter or dunk a dry wooden stick to check if it comes out wet.
  • When the soil is sufficiently dry, it is time to water your cactus. However, make sure to use a controllable spray water bottle instead of a water jug. This helps prevent overwatering and root rot.  
  • Keep spraying water into the potting soil until it feels evenly moist; however, drain out any excess water immediately, as flooding can be extremely dangerous for a growing cactus plant.
  • Finally, mark the day you water your cactus plants on a calendar to ensure you check on the plant’s hydration and health exactly after a week.

Why is it Important to Control Your Cactus Plant’s Watering?

As mentioned above, plants like cactuses are extremely sensitive to hydration. While you may be used to water your other plants every day, it is crucial that you remember your thorny companion thrives on deprivation.

This is why many cacti can live over a hundred years out in the wild despite the extreme living conditions. However, why should you strictly control your cactus plant’s watering routine?

Unlike most plants, cactuses have evolved to have thorns instead of leaves. Since the leaf of a plant has thousands of tiny holes to allow the transpiration and diffusion of water, a cactus’ thorns prevent this movement.

Despite the hot or dry external conditions, a cactus plant will not easily lose water to its atmosphere. Instead, it will be able to retain its hydration and remain fresh for an extended period even when you forget to water it.

Moreover, another unique quality that makes a cactus the perfect dessert plant is its thick trunk. While most plants have thin stems containing a network of plant vessels, a cactus’ trunk can do much more.

Just like a camel with a hump, a cactus can store moisture in its trunk for long periods and live on that moisture during dry and hot weather conditions.

Thus, while your other house plants might depend on your watering schedule, the cactus has evolved and adapted to be very independent and self-sufficient. This means any excess watering is completely unrequired.

Moreover, another critical reason for avoiding over-watering your cactus plant is because it can lead to root rot and cause your house plant’s premature death.

What is Root Rot?

Root rot is a most common and dangerous plant disease resulting from excessive watering or high humidity levels.

Anytime you water your indoor potted or outdoor planted cactus plant more than what is advised, its root cells refuse to absorb more water than their cell capacity.

This causes all the excess water to accumulate inside the cactus plant’s potting soil, creating excessively moist conditions ideal for fungal growth.

If any airborne fungal spores are to settle on the wet soil, it will take only a few days for them to reproduce and spread all the way to the cactus plant’s roots.

As soon as the fungus grows over the roots’ surface, the roots begin to decay and die. Since fungus tends to thrive on dead plant matter, the root rot only accelerates and worsens the overall fungal infection.

Eventually, as most of the cactus roots rot away and die, very little water is transported up the plant. Although the cactus can retain its moisture for a long period, it does require some water from time to time.

Since no more water is being carried up the plant, its trunk’s water reserves get used up and the plant dehydrates. This leads to an immediate decline in the rate of photosynthesis, which thus affects the cactus plant’s ability to produce its necessary plant food.

As a result, the cactus begins to dry up and lose its thorns before it dies.

How to Save an Overwatered Cactus Plant?

While it is quite challenging to save most house plants once a fungal infection eats away their roots, a cactus plant’s natural endurance and remarkable resistance allow it to fully recover from infection if the correct measures are taken at the right time.

Hence, if you notice your cactus plant’s dry, dull, and frail appearance, follow the steps below to recover its health.

  1. Begin by digging out your cactus plant from its pot or the ground. It is important that you use a small shovel to prevent further root damage.
  2. If the indoor cactus plant is too big, tilt its pot to the side and seek another person’s assistance to slide it out.
  3. Moreover, ensure that the cactus plant’s root ball remains intact and none of its trunks break off during the process.
  4. Once your plant is out, place the root ball under running water to remove the wet soil and wash the roots.
  5. Use a soft-bristled brush to examine the condition of the roots further before you proceed to the next step.
  6. Next, take a pair of pruning shears and trim away all dead and decayed root bits. Once the cactus is left with only healthy roots, gently spray them to restore some hydration.
  7. Fill up half the pot with a batch of high-quality and well-draining potting mix and place your cactus inside. Hold your cactus from its trunk as you fill the rest of the pot with the mix, and pat it down to ensure stability.
  8. Finally, add water to your repotted cactus plant using a spray bottle, and leave it under the sun.

Cactus Plants (Mix of 6), Mammillaria Cactus Plants Live in Cactus Soil, Opuntia Cactus Live Plants, Cacti Plants, Cactus Décor Succulent, Cacti Décor Drought Tolerant Plants by Plants for Pets

Final Thoughts

Although most species of the Cactaceae family have excellent immunity and resistance, overwatering can still kill them.

Thus, it is important that you water your cactus plant only when its soil has fully dried up and examine its health every other week to keep an eye out for root rot.

You may also like: