Cacti are known for their unique beauty, resilience, and low maintenance requirements. However, like any other living organism, cactus need water to survive and thrive. While many people assume that cacti can survive for months without water, this is not always the case. In fact, failing to provide your cactus with adequate water can lead to stunted growth, wilted appearance, and even death. So, how do you tell if your cactus needs water? In this comprehensive care guide, we will cover everything you need to know to keep your cactus healthy and happy.
Understanding Cactus Watering Needs
Before we dive into the signs that your cactus needs water, let’s first understand their unique watering needs. Unlike other plants, cacti are desert plants that have adapted to survive in dry and arid conditions. They have thick, fleshy stems and leaves that store water, which allows them to survive for long periods without water. However, this does not mean that they can survive without water altogether.
Signs That Your Cactus Needs Water
There are several signs that you have a dehydrated cactus. Here are the most common ones:
Wrinkled or Shriveled Appearance
One of the most obvious signs that your cactus needs water is a wrinkled or shriveled appearance. When you’ve got a dehydrated cactus, its stems and segments will start to shrink and wrinkle. The skin may also appear dry and brittle.
Dull, Discolored, or Soft Spines
Another sign that your cactus needs water is dull, discolored, or soft spines. When your cactus is dehydrated, its spines may lose their color and become dull or discolored. They may also feel soft to the touch.
Soft and Mushy Stem
If your cactus’s stem feels soft and mushy, it is a clear sign that it needs water. A dehydrated cactus will have a soft and mushy stem that feels spongy to the touch. Don’t confuse this with overwatered. An overwatered cactus will liquefy in your hands.
Crackling or browning
Your dehydrated cactus may have brown, crackling, scab-like areas on the skin.
Lack of water prevents normal growth and development in a dehydrated cactus.
When a cactus is severely dehydrated, it may start to uproot itself from the soil. This is because it is trying to find water, and it can no longer anchor itself in the soil properly. Your cactus needs water.
Signs of Dehydration in Ribbed Cactus
Ribbed cacti like Saguaro will visibly shrink and their ribs will become less pronounced when dehydrated. Here are some specific signs ribbed cacti exhibit during dehydration:
- Decreased overall size/volume – A fully hydrated saguaro can swell substantially with water, but during drought it will shrink considerably smaller as water is lost.
- Sunken ribs – When water storage is depleted, the ribs will sink inwards rather than staying prominently raised. This makes the overall profile more angular/concave rather than rounded.
- Loss of glossiness – The waxy cuticle on hydrated cactus skins helps reflect sunlight and look full/shiny. Dehydrated surfaces will appear more dull and matte in color/texture.
- Less plump pads/sections – Individual self-contained pad-like sections on columnar cacti will flatten out and lose their plump, rounded appearance when water-depleted.
- Wrinkling/folding of skin – As cacti shrink downward due to loss of internal water pressure supporting their structure, skin may start to ripple, crease or fold where ribs meet during dehydration.
So in summary, ribbed cacti become visibly deflated, angular, dull-looking and shape-changed when lacking adequate internal water stores during drought. Their accordion-like qualities really show the process.
How Often to Water Your Cactus
Now that you know the signs that your cactus needs water, the next question is how often to water it. The frequency of watering your cactus depends on several factors, such as the type of cactus, the size of the pot, the climate in your area, and the time of year.
Factors That Affect Watering Frequency
To determine how often to water your cactus, consider the following factors:
- Type of cactus: Some cacti, such as the Christmas cactus need more water than others.
- Size of the pot: The larger the pot, the longer it takes for the soil to dry out.
- Climate: If you live in a hot and dry climate, your cactus may need water more frequently.
- Time of year: Cacti require less water during the dormant winter months than during the active growing season.
Watering Schedule for Different Types of Cacti
As a general rule, cacti should be watered more frequently during the growing season and less frequently during the dormant season. Here is a rough watering schedule for some of the most common types of cacti:
- Desert cacti: Water once every 2-4 weeks during the growing season and once every 4-6 weeks during the dormant season.
- Forest cacti: Water once every 1-2 weeks during the growing season and once every 3-4 weeks during the dormant season.
- Christmas cactus and other epiphytes: Water once every week during the growing season and once every 2-3 weeks during the dormant season.
How to Water Your Cactus
Now that you know how often to water your cactus, the next step is to learn how to water it properly. Here are some tips to keep in mind:
Preparing the Water
Always use room temperature water when watering your cactus. Cold water can shock the roots, and hot water can scorch them.
Additionally, it’s best to use filtered or distilled water, as tap water may contain minerals that can build up in the soil over time.
Techniques for Watering Your Cactus
There are two main techniques for watering your cactus: bottom watering and top watering.
Do you water cactus from the top or bottom?
- Bottom watering: Fill a saucer with water and place your cactus pot on top of it. The soil will absorb the water through the drainage holes in the bottom of the pot. Once the soil is moist, remove the pot from the saucer.
- Top watering: Use a watering can with a long spout to water your cactus. Water the soil around the base of the plant, taking care not to get water on the stem or leaves.
How much water does a cactus need?
Here are some tips on how much water a cactus needs:
- Remember, cacti are adapted to thrive in arid desert environments and don’t need frequent watering. Overwatering is much more dangerous than underwatering for most cacti. You can’t un-mush a mushy cactus!
- During the growing season in spring and summer, water when the top few inches of soil become completely dry. This may mean watering once every 2-3 weeks on average.
- In the fall and winter, allow the soil to dry out even longer between waterings – up to 4-5 weeks. Reduce watering frequency since growth has slowed.
- For most common cacti like desert cacti, Christmas cactus, etc. aim to water deeply but infrequently. Soak the whole root zone until water drains from the bottom, then don’t water again until it is dry.
- Small amounts of water frequently can lead to shallow roots and rot. Deep soakings encourage deep, hardy roots that can reach into deep pockets of moisture in the soil if planted in the ground. A few times before the heat really turns on in Southern California, I like to completely saturate the ground where all of my succulents and cacti are planted so that it can really soak down and encourage the roots to reach as far down as possible.
- The exact watering frequency depends on factors like climate, soil type, sun exposure, and size/type of cactus. Get to know your plant’s needs and they’ll be much better off for it.
- Provide fast-draining soil and pot with drainage holes. Cacti should never sit in wet soil.
- Water amounts vary by size. A 2 inch cactus may need a few tablespoons every 2-3 weeks. A large barrel cactus may need gallons.
- Look for visual cues like wrinkling and deflating to tell you when you’re gonna want to water. The soil drying out completely triggers watering time.
Tips for Proper Cactus Watering
To ensure proper cactus watering, keep the following best practices in mind:
Use a Suitable Container
Choose a container with drainage holes to allow excess water to drain out of the soil. This will prevent water from accumulating in the bottom of the pot, which can lead to root rot.
I firmly believe that all plants should have drainage holes.
Use Quality Soil
Use a well-draining soil mix specifically designed for cacti and succulents. This type of soil will allow water to flow through it easily, preventing water from sitting in the soil and causing root rot.
Overwatering is one of the most common mistakes people make when caring for cacti. Remember, cacti are desert plants that can survive for long periods without water.
If you water your cactus too frequently, you risk drowning the roots and causing root rot.
Knowing when your cactus needs water is essential for keeping it healthy and thriving. By understanding the signs that your cactus needs water, how often to water it, and how to water it properly, you can ensure that your cactus remains a beautiful and resilient addition to your home or garden.
Remember to keep in mind the tips for proper cactus watering, use quality soil, and avoid overwatering. With these tips, you can be sure that your cactus will thrive for years to come.
More about cactus roots here: Exploring Cactus Roots: An Important Part of Their Survival in the Harshest of Conditions