How Often Should You Water a Cactus (A Complete Guide)

By | Updated December 7, 2023

Water your cactus once a week, adjusting based on climate. When it’s hot in summer, increase frequency to twice a week; cut back to every two weeks in winter. Use the “soak and dry” method, ensuring deep watering and allowing soil to dry before the next session. Adapt to your cactus species and environment for optimal health.

Cacti, an incredibly diverse plant species, boasts over 2,000 distinct types worldwide.

Despite their diversity, they share a common characteristic—they are remarkably low-maintenance, making them a favored houseplant.

Unlike typical plants, cacti don’t demand daily watering. Instead, they thrive with intermittent yet regular watering. Striking the right balance is crucial for their survival.

This article will explore how often should you water a cactus plant to ensure its sustained health over the years.

How Often Should You Water a Cactus Plant

Cacti are very low-maintenance plants. They only require occasional watering and can prosper without much attention. They are not like other plants that require a lot of care.

You should water a cactus plant at least once a week. If there is a lot of rain in your area (more than an inch per week), you should water once every three or four weeks to prevent overwatering, which can cause root rot.

The best time to water your cactus is after the soil has dried out but before it gets hot outside.

The heat from the sun will dry out the plants quickly, so you’ll want to try to give them enough water while also preventing hydration when it’s too hot for their roots.

If you’re using an automated drip system on your cactus, this should be done once or twice each week, depending on how often they go through cycles of wetting and drying out during warmer weather conditions.

Not only will watering your cactus regularly help it to grow, but it also encourages blooming.

Cactus Watering in Summer

Most people water their cacti once a week during the summer, but this can vary.

Watering more often is fine as long as you don’t overwater.

If your soil is dry for several days and doesn’t rain, give your cactus some extra watering to stay hydrated and healthy.

The temperature is usually hotter in summer, and your cactus will need more water than in winter.

If you live somewhere very hot where it becomes over 100 degrees Fahrenheit during summer days, you might want to water twice a week if they are indoors or near a window because of the extra heat.

When growing cacti outdoors, you should aim to water once or twice a week during summer. Don’t worry about watering them the next day if it rains.

But if it is dry, give them more water so they don’t get flushed out.

If you live in a cooler climate with weather fluctuations of hot and cold temperatures or freezing winters, your cactus will require less water than the ones grown somewhere warmer with the regular summer heat.

Keep an eye on their soil to ensure that all parts have access to moisture when the temperature drops below 50 degrees Fahrenheit.

Cactus Watering in Winter

During winter, when your cactus will be dormant and slow down its growth – it won’t need as much water because its metabolism is slower due to the cold temperature outside.

Generally, you should water your cactus once every two weeks during winter. Ensure the soil is completely dry before watering again, and then let it drain fully.

You’ll want to avoid overwatering your cactus during winter because cacti are dormant, which means they have slower metabolisms. If you overwater them, it will cause the roots to rot, which can kill your plant.

On the other hand, if you allow too much time between watering in winter when they’re slower growing and not requiring as much water, their chances of being killed by the cold increase.

Therefore, err on caution when in doubt and water your cactus approximately once every two weeks during winter.

If you live in a climate with very cold winters (below USDA Zone #11), do not water during dormant periods because this could encourage growth, which isn’t suitable for your location.

Watering Cacti That Are Not Dormant

If you live in an area where the winter is mild and temperatures don’t drop below freezing, you may wish to water your cactus more frequently if they’re not dormant.

Some cactus species do not need a dormancy period during the winter months. These cacti require more frequent watering than the average cactus.

During this time of year, you should water your plant once every week or two weeks.

During these months, ensure the soil is completely dry before watering again, and then let it drain fully.

If you have a fast-draining potting mix – this will also help prevent overwatering, which can cause root rot in winter when temperatures are milder.

When to Water Indoor Cacti

Cultivating cacti indoors requires a distinct approach compared to outdoor cultivation. Several crucial factors demand consideration.

Begin by assessing your pot’s size and the presence of drainage holes.

Inadequate drainage due to small holes leads to overwatering, while excessively large holes may result in plants drying out prematurely.

A practical method to ascertain the right pot size is to gauge its weight. A heavier pot indicates sufficient potting mix for effective drainage.

For those nurturing indoor cacti in containers, various factors influence the watering schedule, including the cactus type, indoor humidity levels, and seasonal variations (fall/winter being drier than spring/summer).

Maintaining consistency in these variables permits a watering frequency of once every one to two weeks.

However, caution is paramount—avoid over-watering. Cacti, being desert plants, are particularly sensitive to excess moisture, which can swiftly jeopardize an indoor cactus garden.

To enhance aeration and drainage, consider adding a layer of grit or gravel to the container’s bottom.

This proactive measure minimizes the risk of overwatering, contributing to the overall health of your indoor cacti.

When to Water Outdoor Cacti

Caring for outdoor cacti necessitates distinct practices compared to indoor cultivation, especially in regions with colder climates. Most desert cacti, subtropical or tropical rather than hardy, cannot withstand temperatures below 40 degrees Fahrenheit.

Generally, outdoor cacti should be watered approximately once every two weeks during the spring and summer, with variations depending on your location. In hotter climates, these plants may require watering every week or two. Assessing soil moisture by feeling it with your finger is reliable before watering cacti in warmer regions.

While watering cacti is not overly complex, several factors influence the frequency and timing of watering, such as the cactus species and soil drainage. Some cactus species require less water, and watering frequency is reduced in loose, well-draining potting mixes.

Cacti, being desert plants, exhibit resilience to drought conditions. If you reside in an area with regular rainfall, a watering schedule of once every two weeks is likely sufficient. Allowing the cactus to dry out between watering is advisable. If the soil appears moist, refrain from watering; reassess the soil the following day for uncertainty.

In regions with low humidity (below 30%), outdoor cacti may necessitate more frequent watering. When cultivating cacti in the ground, ensure the soil is well-draining, typically a mix of sand and dirt. Add gravel if needed to enhance drainage.

Initially, cacti are drought-resistant and usually do not require watering after planting or transplanting. However, this may change based on seasonal rainfall patterns. In drier periods, consider increasing water intake gradually, approximately an inch every few weeks. Adequate drainage is crucial to prevent overwatering.

Occasionally, applying a layer of mulch on top of the soil or placing gravel at the bottom can benefit cacti. This practice helps retain moisture and prevents the growth of weeds or grass.

How Do You Know When a Cactus Needs Water

Cacti need different amounts of water depending on their size and species. Small cactus plants require less frequent watering than larger ones, as they dry out more quickly.

Generally, the plant needs water if your cactus’s soil is dry.

Sticking your finger down about two inches to test whether the soil is dry. If it’s moist, wait a few more days before watering again.

If you water too often or not enough, cacti will suffer from root rot and other issues that jeopardize their health and longevity.

Because of this, it’s critical to identify an overwatered and underwatered cactus.

Signs of Overwatering

An overwatered cactus is far more common than an underwatered one. It looks like it’s in the process of rotting away.

The soil will be wet and mushy, with roots that are beginning to rot as well. Sometimes, mold grows on top of the potting soil or all over the plant itself!

An overwatered cactus is usually soft and mushy to the touch.

The leaves may droopy or fall off, a common sign of root rot in many plants.

It’s not only the outside that gets affected when watered too often; poor drainage can also cause problems inside.

If soil remains waterlogged for extended periods, roots will begin to rot from constant submersion in liquid. When they die, so does the plant.

How To Save an Overwatered Cactus

To salvage an overwatered cactus, the most effective approach involves excising the rotted sections of the plant.

If confronted with an extensive root rot issue, discarding the entire pot and commencing anew with fresh soil may prove optimal.

When dealing with localized root rot, surgically remove any brown or slimy segments before transferring the cactus to a container filled with fresh soil.

A simple repotting with judicious watering is often adequate for a robust recovery.

It’s crucial to strike a balance, ensuring the cactus receives periodic watering without excess. Keep in mind their need for intermittent water and exposure to bright light.

Root rot, a consequence of overwatering, poses a swift threat to plant life. The key preventative measure is administering water sparingly to avert this detrimental condition.

Signs of Underwatering

An underwatered cactus is less common than an overwatered, but it’s still possible.

A cactus experiencing insufficient water may seem outwardly healthy with no wilting leaves, mold development, and all spines appearing sharp and upright. However, its internal condition tells a distinct tale.

The soil will feel dry – too dry! And if you dig below the surface, you might find that it has shrunk away from where roots should be growing to take up their share of moisture. At this point, they’re dead.

The plant itself will be very dry and brittle to the touch. If you squeeze it, nothing comes out; no water at all!

While this might not cause an instant wilting effect as overwatering can, it also means that your cactus won’t drink up anymore when watered, so it’ll just keep getting drier and smaller until you decide to take action.

How To Save an Underwatered Cactus

The most effective approach to revive an underwatered cactus is often thorough watering.

For severely dehydrated cacti, repotting into fresh soil can address the issue. Ensure consistent watering over the next few days to facilitate recovery.

Alternatively, provide a substantial soak and carefully squeeze out excess water. Suppose your cactus has begun to shrivel or collapse; fear not. Adequate watering will prompt a swift rebound—just be cautious not to overwater in subsequent care.

When water-starved, cacti may droop significantly before reinvigorating within an hour or two. This response results from rapid water absorption by dehydrated cells, which plump up as moisture is reintroduced.

Whether opting for repotting or maintaining the existing container, allow the soil to dry before the next watering. Aim for a weekly watering schedule when necessary, as excessive soil moisture can lead to rot, mirroring the issues caused by insufficient hydration.

In uncertain situations, prioritize underwatering over excessive watering for your cactus. While overwatering is noticeable and can be remedied by allowing the soil to dry, the recovery of underwatered plants may extend over weeks or months, even with attentive care.

Maintain hope during the recuperation process, but also recognize the need to give them time to recover from the stress of dehydration.

How Long Can a Cactus Go Without Water

A desert cactus can go up to two years without water because its thick stems store the little moisture it needs.

They will slowly lose their energy and color during this time, but they will not die.

However, if the cactus is in a pot, it can only survive six months without water because its roots need moisture.

A succulent has various ways of conserving water to live long periods without it or store enough moisture even if there are dry spells.

However, even if they can go for a long time without water, regularly giving them enough is still important.

Cacti and succulents should be watered once the soil has dried up because overwatering or underwatering will cause damage such as root rot or wrinkling of leaves.

How Much Water Do Cactus Plants Need?

The water needs of a cactus vary by species. Most cacti generally need between one and two tablespoons of water per week.

However, if the cactus is in a warm, dry area, it may need more water. Your cactus will require less water if you live somewhere cold or humid with little sunlight.

If it’s wintertime and freezing temperatures are approaching, wait until spring to increase how much water you give the plant.

Likewise, a small cactus in a small pot will require less water than one in a large pot because the soil dries out faster.

In addition to the type and size of the cactus, other factors affect the amount of water your cactus needs:

  • The temperature and humidity in its environment
  • How much exposure it has to sunlight
  • Soil type

If you have a cactus exposed to lots of sunlight, it will need more water than one in low light.

The same goes for high humidity or cold temperatures – the plant needs less water if its environment is very dry and hot instead of wet and cool.

The soil type greatly affects how much water your cactus gets.

High-quality, well-draining soil will need less attention than inferior soil that doesn’t drain as quickly because the plant won’t get enough hydration.

If this is the case for you, try adding sand or perlite to increase drainage and aeration of the root zone.

How To Water Your Cactus Plants

Watering your cactus properly is vital for its health, given its unique adaptation to arid conditions.

Here are two key strategies to ensure effective cactus watering:

  • Deep and Infrequent Watering: Cacti, designed for survival in sporadic rainfall, benefit from infrequent but thorough watering. Avoid shallow, frequent sessions and let the soil completely dry between waterings to prevent overwatering and potential root rot. When watering, ensure deep penetration to reach the roots, fostering the development of a robust root system that enhances the cactus’s resilience to drought.
  • The “Soak and Dry” Method: A reliable technique for cactus care is the “soak and dry” method. Thoroughly saturate the soil during each watering, allowing it to dry out fully before the next session. Implement this by watering until the excess drains from the pot and patiently waiting until the top inch or two of the soil is dry before the next watering. This approach avoids overwatering and stimulates healthier cactus growth with deeper root systems.

It’s important to consider the specific needs of your cactus species, as requirements may vary among varieties.

Applying these watering techniques provides optimal conditions for your cactus, promoting robust growth and longevity.

Final Thoughts

Cacti are desert plants that have adapted to live through periods without water, but this doesn’t mean they don’t require any water.

Frequent watering is necessary to provide enough moisture and keep the cactus hydrated.

This will allow the plant to grow strong roots and stems instead of growing spindly ones like a plant that isn’t receiving enough water would do.

In short, the best way to know when to water a cactus is to keep an eye on the soil, and when it starts looking dry, it’s time to water again.

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