The bunny ear cactus (Opuntia microdasys) is an attractive succulent that sometimes blooms in the spring. It is relatively easy to grow but requires specific sunlight, temperature, and water conditions. If you do not meet these requirements, it will shrivel and die.
Your bunny ear cactus is shriveling because it’s underwatered or overwatered. Various environmental factors contribute to why gardeners make mistakes in watering bunny ear cacti, such as extreme temperatures, inadequate soil drainage, and sunlight intensity.
This article will discuss why your bunny ear cactus is shriveling and share tips on fixing the issue. Read on to learn more about how to get those cute bunny ears up and perky again!
1. You Are Underwatering It
Bunny ear cacti are generally drought-tolerant, leading to many novice gardeners believing it’s acceptable to leave them unwatered for extended periods. While this may be true to a certain extent, constant neglect will kill even the sturdiest succulents.
Like many other cacti, the bunny ear cactus absorbs water from the soil and stores it in its fleshy stems, often called pads. This mechanism enables the plant to remain hydrated longer than other plants.
However, during long periods of drought, it is typical for the bunny ear cactus in the desert to shrivel from the lack of water. As the plant uses up the moisture stored in its pads, it dries up and may eventually die if it doesn’t get enough water to replenish what was lost.
When grown in pots indoors, your bunny ear cactus depends on you entirely for its water needs. Thoroughly watering the plant once a week during the summer and less frequently during the cold months should suffice.
How to Fix
If you suspect your bunny ear cactus is shriveling from underwatering, you can water the plant deeply until you see the excess dripping out of the drainage holes. This will allow the pads to soak up enough moisture and bounce back.
To prevent this from happening again, inspect your potting mix around 5-7 days after watering to see if the soil’s upper 1-2 inches (2.5-5 cm) are dry. If it feels dry, water the plant again. Otherwise, give it a few more days and check again.
2. You Are Overwatering It
Since the bunny ear cactus is drought-tolerant, it’s safe to allow the soil to dry a little until the next watering. Most succulents don’t like sitting in consistently moist soil and are more likely to suffer root rot than other houseplants.
It’s easy to overwater the bunny ear cactus in winter because the soil stays damp for longer. Always check the soil before adding more water to prevent keeping your plant in water-logged conditions.
One of the first signs that your bunny ear cactus is being overwatered and developing root rot is brown spots on the pads. Eventually, as the roots rot, your plant won’t be able to absorb enough moisture, causing the pads to shrivel.
How to Fix
Inspect the roots to see the extent of the root rot. If over 50% of the roots have turned black, it may be best to dispose of the plant and the potting mix. Chances are the fungi that caused the disease are thriving in the soil and the plant’s roots.
On the other hand, if the roots are white and plump, you can still save your bunny ear cactus.
Here’s how to do it:
- Gently dry the roots with a clean towel.
- Re-pot the plant using a fresh pot with a new and dry potting mix.
- Place the plant next to a sunny window and wait a few days before watering it.
You can learn more about how to fix an overwatered bunny ear cactus by reading my other article, Why Is Your Bunny Ear Cactus Falling Apart?
3. The Temperature Is Too High
Bunny Ear cacti are desert plants native to Mexico and, therefore, tolerant of high temperatures. However, high temperatures also mean the soil tends to dry up faster. If your plant doesn’t receive enough water in such conditions, it’s likely to dry up and shrivel.
Although deeply watering your bunny ear cactus once a week is the usual requirement during warm seasons, you must also pay attention to the temperature, especially when growing your plant outdoors and under direct sunlight.
How to Fix
Make it a habit to check the soil for moisture regularly to ensure your plant doesn’t stay dehydrated for too long. You can check the soil 3-5 days after watering during the peak of the summer and add more water when necessary.
Water your bunny ear cactus early in the morning to absorb the moisture before the sun’s intense heat dries up the soil.
4. The Temperature Is Too Low
The bunny ear cactus can tolerate temperatures up to 100 °F (37.8 °C) in the summer. However, it won’t do very well at freezing temperatures in the winter.
How to Fix
Ideally, you should keep your plant in an area with temperatures ranging from 50 to 65 °F (10 to 18.3 °C) during the cold months.
Outdoors, in USDA zones 7 and below, your bunny ear cactus will most likely die from the frost. If possible, move the plant indoors.
However, suppose you have an overgrown bunny ear cactus growing in your garden, making it difficult to move it indoors. In that case, you can wrap the plant in burlap before the forecasted first fall frost.
You should avoid using non-breathable materials, such as plastic tarp, as these will trap moisture and your plant could become damaged.
5. It Has Inadequate Soil Drainage
Bunny ear cacti thrive best in sandy soil with excellent drainage. When growing them in your garden, you may need to amend your soil regularly to improve drainage. Garden soil becomes more compact over time, making it unsuitable for cacti.
Overly sandy soil drains water out more quickly, possibly leading to your bunny ear cactus being underwatered. Conversely, a potting mix with more loam than sand may retain moisture longer than your cactus prefers.
Therefore, paying attention to your soil’s qualities and how quickly they can drain water is crucial to ensure your plant is adequately hydrated.
Seasonal changes and environmental temperatures can also affect how quickly the moisture evaporates, so it’s a valuable skill to know how to adjust your watering schedule accordingly.
You’ll know your cactus has watering problems based on the discoloration of the pads. Both underwatering and overwatering can lead to the pads’ yellowing, browning, and eventual shriveling.
How to Fix
When growing bunny ear cactus in a pot, you can improve drainage using unglazed clay pots. These pots have excellent moisture-wicking qualities and breathability, allowing the soil to dry up more quickly.
Improve your soil’s drainage by adding more porous materials, such as sand or perlite. It’s more acceptable to grow your bunny ear cactus on a substrate with more drainage than water retention. However, you’ll just need to water it more frequently.
6. It’s Getting Too Much Sunlight
Bunny ear cacti are sun-loving plants that grow best under direct sunlight for 8 hours a day. However, they will still do well in partial shade if they receive at least 6 hours of light daily.
The sun’s varying levels of heat and brightness affect the soil’s water-holding capacity and the amount of moisture lost through the cacti’s pads and spines. Failure to adjust your watering schedule accordingly will result in poor watering and your bunny ear cactus shriveling.
How to Fix
It’s only natural to water your plants more frequently on bright, sunny days to compensate for the moisture lost through evaporation. Conversely, bunny ear cacti need less frequent watering during cold, dark months. Often, once or twice a month is enough.
7. Your Bunny Ear Cactus Has a Pest Infestation
Bunny ear cacti are often targets for plant pests, including mealybugs, aphids, and spider bugs. Left unattended, these pests can suck out the pad moisture, causing them to shrivel.
Aphids are typically pale yellow to brown in appearance and are pretty easy to spot on your cactus’ pads. They are heavy sap feeders and can potentially dry out young bunny ear cacti.
On the other hand, mealybugs and spider mites are white and tiny. Like aphids, they also suck cactus sap, which can dry out your plant in large enough populations.
How to Fix
Here are a few ways to deal with pests on your bunny ear cactus:
- Remove the pests manually as you see them to prevent severe damage. Place them in a tub of soapy water.
- Place sticky traps below your cacti and scrape the pests off using cotton swabs.
- Spay your plant with a mixture of 1 teaspoon (5mL) neem oil and ½ teaspoon (2.5 mL) liquid detergent in 17 fl. oz (500 mL) water. The neem oil will eliminate the pests, while the soap breaks down the oil enough to avoid clogging your cacti’s pads and preventing transpiration.
Several issues can cause bunny ear cacti to shrivel, including the following:
- Poor soil drainage
- Extreme temperatures
- Intense sunlight
- Poor watering practices
The best way to prevent the problem is by adjusting your watering schedule accordingly, depending on the above factors. In addition, it’s crucial to remove the pests before they can damage your cacti and harm the other neighboring plants.