Cactus Watering - Everything You Need to Know! 

Cacti are popular houseplants, admired not only for their unique beauty but also for their ability to survive in harsh conditions. However, the common misconception that they don’t need much water is misleading. While it’s true that cacti thrive in dry environments and prefer less frequent watering, they still need moisture to grow, especially during their active growing season.

So, how often should you water your cactus? In general, you should water your cactus when the soil gets completely dry. To determine if the soil is dry, insert your finger about 2 inches into the soil - if it feels dry at that depth, it's time to water your cactus. 

Overwatering is a common mistake, but don't worry – with the right care, your cactus can live a long and happy life. This isn't always the case because cacti can be found in a wide variety of habitats. There is more to how to water a cactus than when to water it; you also need to know the correct cactus soil porosity, container drainage, site conditions, and time of year. 

Don't worry; Planet Desert has got your back. Let's embark on a journey to discover the secrets of watering cacti and ensure they thrive in your care. Let's dive in!  

How to Properly Water a Cactus  

• Before watering, make sure the soil is completely dry. Stick your finger into the soil about an inch deep; if it's dry, then it's time to water.
• Cacti don't need frequent watering. In the spring and summer, during the actively growing season, water your cactus only when the soil is dry or every 2-4 weeks. In the fall and winter, during their dormant season period, reduce watering significantly to once a month or even less.
• Water thoroughly, but let the excess water drain out. Having well-draining soil is crucial for cacti. If planting your cactus in a pot, ensure the pot has a drainage hole. Avoid allowing the cactus to sit in water, and pour water directly at the base, avoiding the plant's body to prevent rot.
• Avoid Overwatering as it is one of the most common mistakes with cacti. Too much water can lead to root rot. Always err on the side of underwatering rather than overwatering.

• Consider the Season, and adjust your watering schedule. Cacti need less water during the dormant season when they are not actively growing.
• Misting is not typically necessary for desert cacti, as they prefer drier conditions. Jungle cacti are a bit different and thrive with some misting. They are adapted to store water in their fleshy stems and don't rely on frequent misting like some other plants. 
• Use appropriate water. Room-temperature water is best; avoid cold water, which can shock the plant.

Signs of underwatering and overwatering cacti   

Underwatering can cause the cactus to become dehydrated and stunt its growth, while overwatering can lead to root rot and other fungal diseases.

1. Underwatering  

Wrinkled or shriveled appearance

When a cactus doesn't receive enough water, it may start to look wrinkled or shriveled. This is a clear sign that it needs more hydration. This can be easily remedied by increasing the frequency of watering and ensuring the soil is well-draining. Over time, the cactus should regain its turgidity and healthy appearance.

Dry and brittle stems

The stems of an underwatered cactus may become dry and brittle to the touch. They may also appear thinner than usual. To revive a cactus with dry and brittle stems due to underwatering, thoroughly water the plant until the soil is moist but not waterlogged. Consider repotting the cactus in well-draining soil to prevent future issues with dehydration.

 

Slow or stunted growth

Insufficient water can hinder a cactus’ growth. If you notice that your cactus isn't growing as quickly as it should, it might be a sign of underwatering. 

2. Overwatering  

Soft or mushy stems

Rot spots on an overwatered cactus, causing the stems to become soft or mushy. If you notice a squishy texture or discoloration, it's likely due to excessive moisture. 

Root rot

Overwatering is one of the most common problems with cacti. This can lead to root or stem rot and other issues. To avoid overwatering, it is important to allow the soil to dry out completely between waterings. The cactus should also be planted in well-draining soil and a pot with drainage holes. 

Foul odor

If you detect a foul smell coming from your cactus, it could indicate rotting due to overwatering. The smell is often accompanied by a mushy texture in the affected areas. 

Yellowing or browning of leaves

When a cactus receives too much water, its leaves may start to turn yellow or brown. This can be a sign of root damage caused by overwatering. 

Cactus Watering Requirements  

Understanding the specific watering needs of your cactus is crucial. Factors such as the type of cactus, pot size, potting soil composition, bright light, and environmental conditions all play a role in determining the frequency and amount of water your cactus needs. Remember to adjust your watering routine based on the seasons, as cacti may require less water during their dormant period.  

To keep your cacti healthy, we have covered in detail below the best practices for watering them as well as the most common watering errors to avoid. 

How Often Do You Water a Cactus – Based on Location 

When it comes to watering cacti, the frequency can vary depending on a few factors. Generally, cacti don't need to be watered as often as other plants. It's best to water them thoroughly but infrequently, allowing the soil to dry out completely between waterings.  

Indoor Cactus Watering   

• Watering frequency: If you are growing cactus indoors, it's generally recommended to water the cactus every 2–4 weeks, or when the soil is completely dry. This allows the roots to dry out between waterings and helps prevent overwatering.  
• Observation is key: Keep a close eye on your indoor plants and observe their watering needs. Factors such as temperature, humidity, and the type of potting mix used can affect how quickly the soil dries out. Adjust your watering schedule accordingly to ensure the cactus plant's well-being.

Outdoor Cactus Watering  

• Watering frequency: Outdoor cacti typically require less frequent watering due to exposure to natural rainfall. In general, you can water outdoor cacti every 4-6 weeks during the growing season, or when the top few inches of soil are dry. However, this may vary depending on your climate and the specific needs of your cactus.  
• Consider the weather: Consider your local weather conditions. If you live in a particularly hot and dry climate, you may need to water your outdoor cacti more frequently. On the other hand, if you experience heavy rainfall, you may need to adjust your watering schedule to avoid overwatering.  

When to Water a Cactus – Based on Season 

When it comes to watering cacti, the frequency can vary depending on a few factors. Generally, cacti don't need to be watered as often as other plants. It's best to water them thoroughly but infrequently, allowing the soil to dry out completely between waterings.  

How Often to Water in Summer?  

During the growing season, cacti typically require more frequent watering as they actively grow and may have increased water needs because of direct light. It's important to monitor the soil moisture and water when it starts to dry out.  Smaller cacti require more water, while larger ones require additional moisture. However, be cautious not to overwater, as cacti still prefer well-draining soil.  

How Often to Water in Winter?  

Winter is a rest period for many cacti, reducing their watering needs. Smaller specimens can go weeks without watering, while larger ones can survive all winter without moisture. Soak the soil thoroughly after each watering until water begins to drain from the pot's drainage holes. Overwatering is a major issue in the fall and winter months. To avoid overwatering, let cacti dry out more and use a moisture gauge or finger to check the soil.  

How long can cacti go without water? 

It's amazing how resilient cacti can be when it comes to water. Many desert cacti have adapted to survive in arid environments with infrequent rainfall. Some cacti can go a year or even longer without water, relying on the occasional rain that occurs in those regions. While larger cacti can generally handle longer periods without water, it's important to note that the specific water needs may vary depending on the cactus species and its size.  

Most large cacti can easily go 4 to 6 months without water, but it's always a good idea to monitor their condition and adjust watering accordingly.

While cacti can survive with normal rainfall, providing them with a bit more water can help them thrive.

Keep an eye on the signs of a thirsty cactus, like a wrinkled or shriveled appearance, as this can indicate that it's time to give your cactus-like Prickly pear a good drink. However, it's important to remember that each cactus is unique, and its watering needs may vary.

Observing the signs of a thirsty cactus, such as a wrinkled or shriveled appearance, can also guide you in determining when to water. 

Best Soil for Cactus  

Soil plays a crucial role in watering cacti because it affects how water is absorbed and retained by the plant.

A well-draining soil mix allows excess water to flow through quickly, preventing waterlogged roots and potential rot.

Instead, a regular potting soil mix that retains too much moisture can lead to overwatering, which is harmful to cacti.

So, choosing the right soil mix is essential for maintaining the proper moisture balance and preventing water-related issues for your cacti. 

Planet Desert specializes in cactus and has specialized cactus potting soil that includes an organic substrate with mycorrhizae to help with the growth of a healthy root system to help your cacti grow healthy. 

 

Watering freshly rooted cuttings  

Watering freshly rooted cactus cuttings is different from watering well-established cacti. Overwatering can stunt root growth and weaken the plant. Proper watering is essential for a healthy cactus. To properly care for newly rooted cuttings, wait until these desert-dwelling plants show signs of thirst, such as shriveling or wilting. Water the soil to minimize moisture around the base of the cactus, either around the rim or bottom. This encourages roots to sense the water and grow towards it. Water until the root systems are well established and can handle full soaks, ensuring the plant can handle full soaks.  

Can Cactus Be Watered with Tap Water?   

Most people don't think about what type of water to use for cacti and simply use tap water. However, it's important to keep in mind that some tap water may contain high levels of minerals or chemicals that can be harmful to cacti. If you're concerned about the quality of your tap water, you can let it sit out for 24 hours to allow any chlorine to dissipate before watering your cactus. Alternatively, you can use rainwater, filtered or distilled water to ensure the best care for your cactus. Rainwater or distilled water is ideal for cacti as it contains healthy minerals and is safe for watering because it removes impurities.  It's always a good idea to monitor your cactus and adjust your watering routine based on its specific needs. 

Do You Water a Cactus from the Top or Bottom?  

Watering a cactus from the top is the recommended method to avoid overdoing it, instead of bottom watering. Slowly pour the water over the potting medium, ensuring it is evenly moistened. Avoid pouring over the top to avoid black spots or tip rot. When the water begins to flow from the bottom, add enough and discard any that drains out. Never let the water soak.  

How to Know When to Repot Your Cactus?  

Knowing when to repot your cactus is important for its health. Keep an eye out for a few signs. If the roots start to grow out of the drainage holes, or if your cactus becomes too big for its current pot, it's time to repot. Additionally, if you notice the soil drying out too quickly after watering, it might be a sign that the roots need more space. Remember to choose a pot with good drainage and use well-drained soil.  

Key Takeaways