How much should you water cactus plants? This is the most common topic when it comes to cactus and succulent care. When most people think of cactus, they think of the dry desert plants that seemingly need little to no water.
However, cacti can actually be found in many different environments, including the jungle cacti found in tropical rainforests in South America. Cacti have adapted to the harshest of climates and have found a way to get as much water as they need to survive.
So, how often should I be watering my cactus? Generally, during the growing season in the Northern Hemisphere (March through September), cacti should be watered at least once per week to keep them from drying out.
Outside of the growing season, cacti usually only need occasional watering, about once a month, to maintain enough moisture in the soil.
Fortunately, cactus are very hardy plants and can tolerate a considerable amount of water neglect, but there are still several factors to consider when figuring out how much to water cactus.
- Is my cactus Indoors or Outdoors?
- Container Type
- Seasons
- Temperature
- Soil Type
- Species of Cactus and Size
- Humidity
- Amount of Light
Let’s take a closer look at a few of these factors.
Table of Contents
How often do you water indoor cactus plants?
The most common mistake most people make when taking care of their indoor cactus is over watering them. Overwatered cactus and succulents can suffer from root rot, which can oftentimes kill the plant.
On the other hand, underwatered cactus can dry out and suffer from lack of growth and damage to the roots and stems. As a rule of thumb, overwatering your cactus usually causes far more damage to the plant than underwatering it.
Most indoor potted cacti should be watered once every 10 days to 14 days throughout the growing season (March through September).
Loose and well draining soil is the key to preventing root rot in your cactus. Always check to make sure the soil is completely dry before watering.
A quick and easy way to do this is to stick your finger in the soil, at least 2 inches deep, and see if the soil is moist or even colder than the surface. If so, don’t water, and wait a few days for it to dry out some more.
As we mentioned earlier, cacti need less water outside of the growing season, or when they’re dormant. Usually, you will want to water indoor cactus once every three to four weeks during the dormant period.
Things to Consider
There are still certain things to consider when determining the watering frequency for your indoor cactus, like the season, climate, and humidity.
In colder climates during the winter months, we often use indoor heaters which can really dry out the air and affect the humidity.
It’s a good idea to either keep a dish of water near your indoor cactus, or use a humidifier to maintain some moisture in the air. This will help your plant get enough moisture from the air and help keep you from excessively watering your cactus.
Don’t forget to pay attention to how your cactus looks! If you’re seeing it looking a bit pale, and the soil is dry, definitely consider increasing the watering frequency.
What About The Container?
The type of container you decide to use for your indoor cactus definitely affects how often you will be watering your plant. Remember, most cacti thrive in dry soil.
While wider and deeper containers will hold water in the soil longer, small and shallow containers tend to evaporate water more quickly.
The pot material will also play a role in how long moisture will stay in your plant’s soil.
Ceramic
Ceramic pots are a great choice for your cactus. They are usually on the more expensive side, but come with some advantages. Ceramic pots offer some protection from temperature changes, although you should avoid leaving them out in freezing weather to keep them from cracking. Unglazed ceramic pots are porous and allow for good water drainage for your cactus’s soil.
Terracotta
Terracotta pots are another good choice for your potted indoor cactus. Like ceramic pots, terracotta pots provide excellent drainage. However, they do not offer the same protection against temperature changes as ceramic pots. These are also usually less expensive than ceramic pots.
Plastic
Plastic pots with drainage holes can also be a good option for your indoor cactus, provided you keep an eye on how well the soil is draining. Since plastic is not porous like the two types of clay pots mentioned above, water does not drain as quickly. You’ll want to water your indoor cactus less frequently in these pots.
Fiberglass
Like plastic containers, fiberglass pots will hold moisture in the soil longer than ceramic and terracotta pots. You need to make sure the drainage holes at the bottom do not get blocked, otherwise the cactus roots could be sitting in moist soil for too long. It’s best to avoid these types of pots for desert cactus species.
Metal
Metal pots are not ideal for indoor cactus as they often don’t come with drainage holes at the bottom, making watering your cactus a bit trickier. These types of pots are also prone to overheating the cactus if left in direct sun during the hotter summer months.
Wood
Wood pots are another type of container that are best to avoid for your indoor cactus as they hold moisture in the soil and can be very slow to dry out. This prolonged moisture in the soil can quickly lead to root rot in your cacti.
How often do you water outdoor cactus?
Like indoor cactus, outdoor cactus will require more frequent watering during the growing season, and less so when they’re dormant. One of the biggest factors when determining how often to water your outdoor cactus is the season.
Seasonal Watering
Spring
Depending on your climate, you may experience more rainfall during the Spring months. If this is the case, you’ll usually only need to supplement with water at most once per week since this is when your cacti begin their growing season.
Summer
During hot summer months, outdoor cactus should be watered at least once every 14 days, especially when the outdoor temperature is consistently over 90 degrees Fahrenheit.
If faced with extreme heat and little rain, outdoor cactus plants can be watered up to 3 times per week as long as the soil has adequate drainage and is completely dry in between waterings. After an outdoor cactus has been established for a few years, summer watering can be scaled down to once per month.
Fall
This is the end of the growing season and cacti generally become dormant around now, needing less water than in summer. Usually watering your outdoor cactus once per week is enough during the fall season, unless you experience significant heat and dry weather.
Winter
During the colder winter months, there is usually more moisture in the soil as a result of more frequent rain and cooler temperatures. Outdoor cacti can be watered as little as once per month, as long as rainfall is less than 1 inch for a 30 day period. It’s important to check that the soil is completely dry before watering
It’s important to note that seasonal watering for your outdoor cactus is greatly affected by your climate and weather conditions. Always adjust your watering schedule according to the amount of rainfall and daily outdoor temperatures.
Another factor in how often you should water your outdoor cactus, is how recently your cactus was planted. You will want to avoid watering your newly planted cactus for at least one week, as you give your plant’s roots a chance to heal before introducing water.
Size of Cactus
Contrary to what most people would think, the larger and more established a cactus is, the less you’ll need to water it. Basically, because the plant is larger, it is able to store more water, acting kind of like a storage tank.
For example, a large established Saguaro cactus might never need any watering, while a small golden barrel cactus could be watered as much as 2 times per week during hot summer months.
What About The Species?
It’s vital to know the specific species of cactus you’re caring for when determining how frequently it should be watered. As we mentioned earlier, you can find cacti in the hot, arid desert as well as in the wet rainforests.
Depending on the species of cactus, there are different water requirements. Having this information will keep you from accidentally overwatering your cactus plant.
How to Care for Christmas Cactus – (video from Garden Answer)
One example is the Christmas cactus (Schlumbergera x buckleyi), which is found in the tropical rainforests of Brazil. Christmas cacti may require watering more frequently, about once every week when kept in a cool, humid, indoor environment. When kept outdoors in a dry, warmer climate, you may water Christmas cactus 2 to 3 times per week.
On the other hand, you have Prickly Pear cactus, which are native to the dry desert climate. You would only need to water these cacti about once every two to four weeks for their first year.
After the first year, these cacti need even less water. You could water your Prickly Pear cactus as little as twice a month during the summer, and once a month during the remaining months of the year.
How to Water Succulents and Cacti
Watering your cactus plants and succulents is super easy. Many ask if it’s best to water your cactus from the top or bottom of the plant, but most species of cacti do best from slow, deep watering at the base of the plant.
For indoor plants, you can soak the pot until moistures drains through the drainage holes at the bottom of the container.
For outdoor cacti, you can set up a drip system or let water slowly trickle from your garden hose for a few hours to provide a deep soak for your plant.
Many people also wonder “Can I spray my cactus with water?” You don’t want to mist your desert cactus, since they are not native to regions where there is high humidity and surface moisture. On the other hand, jungle cacti like the Christmas Cactus will benefit from the occasional misting.
What does an underwatered cactus look like?
Does your cactus look underwatered? No need to panic, as it’s much easier to revive an underwatered cactus than an overwatered one. Here are some things to look for:
- The cactus may begin to wither after it has used up all of the water it had stored away in its stems and leaves.
- Look for discoloration, particularly a paler shade of green, or even brown.
- Drooping leaves and a wilting body. Once the water is used up, the cactus begins to lose its structure.
- The cactus had dried out flesh and texture. It’s an obvious one, but occasionally overlooked.
If you recognize any of these signs, reviving your underwatered cactus can be as simple as giving it a proper soak. Avoid over watering, and stick to an appropriate watering schedule.
What does an overwatered cactus look like?
With all of this talk about how often to water cactus, it’s helpful to know what an overwatered cactus looks like. There are a few major signs your cactus is overwatered.
Loss of color and turning yellow
Your cactus may turn pale and dull in color. The green color of the cactus may begin to turn yellow as it suffers from chlorosis, a condition in which the plant does not have enough nutrients to synthesize chlorophyll. This is what is responsible for the green color of the plant.
Soggy and drooping cactus and stems
The cactus may begin to be soggy and droopy as excessive water causes the plant’s cells to swell and rupture, damaging the structure of the cactus.
Edema
Edema (oedema) is another sign of an overwatered cactus. This is when blisters and bumps are left on the plant from the epidermal cells to stretch and collapse. You may notice these bumps as brown colored, with a cork like texture.
Root Rot
Root rot is the most telling sign that you have an overwatered cactus. Unfortunately, by the time you realize you have root rot, it’s sometimes too late.
It’s usually hard to see if you have root rot since the roots are not visible. This happens when the roots of the plant are not given sufficient time to dry in between waterings, and they suffocate, in a sense. Ultimately, your cactus will turn black and die if root rot is not detected early enough and corrected.
Some Tips for Saving Your Overwatered Cactus
Some good news. It’s not necessarily the end of your cactus if it’s been overwatered. If you spot the signs early enough there are a few steps you can take to save your plant.
Replant with new, dry soil
So you’ve determined that your cactus has been overwatered. The first thing you can do is replant your cactus in new, dry soil.
Remove your cactus from its existing pot, or soil, and check for any signs of root rot. If you spot any rotted sections, cut them away with a clean, sharp knife.
Make sure you completely remove all rotted flesh, as it could spread again once the cactus is repotted.
Remove all dying cactus stems and leaves
Before replanting your cactus, be sure to remove all the damaged and dying stems and leaves. This will prevent any potential rot or decay from spreading further on the cactus.
Wait one week until watering again
After replanting your cactus, it’s important to wait at least one week before watering your plant. Only a light watering is necessary, as your cactus’s roots are still getting established in the new soil.
From here on, you can implement a proper watering schedule, taking into account all of the factors we previously discussed.
Final Thought
There’s definitely a lot to consider when figuring out how much and how often you should water your cacti and succulents. It’s easy to find yourself overwatering them if you haven’t had experience with these plants before.
Just remember these few simple rules of thumb:
- Better to underwater than overwater your cactus
- You can get by with water once every 10 days during growing season, and once a month in the winter
- Always make sure the soil is dry before watering
Once you have some time to learn what your plant needs, figuring out when to water them will become second nature.