Opuntia Microdasys: The Peter Rabbit of Cacti

Ed Wike
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Quick Care

You’ll know an Opuntia (oh-PUN-shuh), more commonly known as a prickly pear or sabra, by its iconic pad-like paddles. The prickly pear is the trademark of the Southwestern desert, along with the saguaro.

Although it might look like an imposing display, these cacti are relatively easy to take care of, making them a great choice for plant first-timers. There are around 100 species of Opuntia worldwide, but the most popular variety for home cultivation is the Opuntia Microdasys. It has the same prickly pear shape as its taller cousins, but the paddles are only 1 to 1.5 inches (2.5 to 3.5 cm), and it only grows to about 6 inches (15 cm) tall. Not only that, it also has a relatively slow growth rate, so you can keep your Opuntia Microdasys for many years.

All About Opuntia Microdasys

Last, but not least on the list of exotic cactus plants, we have Opuntia microdasys. This opuntia is also known as the desert-dwelling bunny cactus. This adorable looking cactus is often found sprawling along the ground in the deserts of California and Mexico. These odd little plants have been nicknamed the bunny due to the way their spines wiggle and bounce as they poke and prod at their victims looking for food. You might think that the name is quite fitting for this plant, but you just have to see them in action. The way that these spines wiggle as they reach for a tasty morsel is downright hilarious. Some have even said that watching the bunny cactus in action is right up there with watching babies and dinosaurs.

If you love this plant, you are not alone. In fact, many people feel the same way. The Opuntia microdasys are actually rather common. They are distributed all throughout the deserts in California and Mexico and are generally only spotted along the ground during the spring. During the fall the bunny cactus can apparently climb up on rocks and will eventually turn red during the winter months. This red color is actually its defense mechanism. It would seem that the redder the Opuntia microdasys is, the more toxic the spines become.

Types of Opuntia Microdasys

One of the most revered types of cacti is the prickly pear. This cactus is known for its unusual stem which is flat, long, and round in appearance. This stem also has tiny spines which give it its prickly appearance. The word prickly pear actually comes from the plant’s fruit. The fruits of the prickly pear look like prickly pears. The plant originated in Africa and is considered a weed in Australia. The prickly pear has many varieties within it. Several plants are simply different colors of the same plant, while others are unique varieties altogether.

Opuntia Microdasys, also known as the Peter rabbit of cacti is also found in Africa. However, it is found naturally in the South African dessert. There are many varieties of this cactus and those found in the dessert are usually pink and white, whereas those found further north, are green or a grayish-green color.

Opuntia Microdasys Care

The Opuntia Microdasys is an indoor/outdoor cactus that thrives on neglect. It is an extremely hardy plant, and is even suitable for dish gardens.

This cactus is always found in protected areas in the wild, but can easily be grown indoors with bright or indirect sunlight.

It thrives on neglect, so if you have a bit of time to forget to water it, do so. Between waterings, simply mist the plant to keep the leaves hydrated.

Opuntia Microdasys is a very slow growing plant, but in a few years will produce beautiful purple flowers in late spring.

Water it periodically, when the soil feels dry to the touch. This is normally once every two weeks. This is the best way to determine if you need to water the plant. If the soil stays dry for too long, it can actually die.

Light & Temperature

Opuntia microdasys are very happy growing outdoors in sunny areas during warm weather. However, for growing them indoors, it should be noted that they do require either high temperatures or continuous light.

O. microdasys will tolerate cooler temperatures provided they are in sufficient light and provided the nights are cool. If the nights get too warm, they will likely require cooling.

Opuntia stanlyi is pretty tolerant of many climates and conditions, but it does enjoy warm weather and cool nights. In a northern climate it will likely need a little help to stay warm.

When growing out Opuntia microdasys and Opuntia stanlyi within the borders of California, you can assume they prefer daytime temperatures of 75-90F and nighttime lows of 60-70F. These plants will be happiest if the daytime temperatures are between 80-90F and the nightly temperatures between 65-75F.

Water & Humidity

Water and humidity are of utmost importance for the well being of this cactus since many of the cactus' needles are on the ground, it's subject to changes in humidity in the environment. Too much humidity and the cactus will be subject to root rot, too dry and the cactus will wilt. Preventing moisture from evaporating too fast and keeping the soil moist is the best method.

As with all cactus, it's the combination of good drainage and proper watering, along with the correct location that will lead to your cactus thriving.

Prior to planting your cactus, prepare a good soil and ensure good drainage. Use a pot with drainage holes alongside a layer of rocks and a layer of gravel. Place these in a tray beneath the pot should there be too much water in the tray, it'll drain through the rocks and gravel and prevent harmful root rot. Take care that the pot doesn't sit on the rocks. The rocks prevent the pot from sitting directly on the soil which causes water to pond and stay.

Water your cactus when the soil has dried out somewhat. It's important to water it until the water comes forth from the drainage material and no longer dries. This way the soil will always stay moist, but you're ensuring that moisture doesn't stay too long and cause your cactus to rot.

Soil

The soil in which you grow your bonsai trees is one key to its survival and growth. There are different soil mixes to choose from, depending on how quickly you want your tree to grow.

Fertilizer

There are many different options available when it comes to cactus fertilizers. You can use either a slow release fertilizer, organically derived fertilizer, or chemical cactus fertilizer. Generally speaking, slow release fertilizers are most common. They allow for a constant, low stream of nutrients while organically derived fertilizers can be considered something of a gamble, as they are usually made with cactus compost. Finally, chemical fertilizers and slow-release fertilizers are not recommended for certain types of cacti like the Barrel cactus.

Green fertilizer comes in granular form and is mainly used for house plants, due to the high nitrogen content. It is not recommended for rock garden or cactus plants. Green cactus fertilizers usually have a very high nitrogen content, which is too rich for cacti. The high energy of nitrogen may stimulate the plant growth too much, which can result in weak stems. The excess nitrogen can also cause the plant to become too soft. Over time, the soft stems will lose their color and turn brown.

Repotting

Cactus: Is It Necessary?

If you would ask the average person, they wouldn’t believe that not all species of cactus should be repotted. Cacti are sometimes referred to as “stubborn” and “difficult” because they naturally want to be left alone. They are not the type of houseplant that bring out the green-thumbed enthusiast.

The best way to address the needs of cactus is to understand how Western culture and the right mindset towards care methods can help ensure its longevity.

Propagation

There is no definitive information on how long a cactus can live. The oldest healthy specimen in the United States is over 130 years old and is named the "Methuselah" cactus. Trichocereus peruvianus is considered to be the longest living plant with an average lifespan of 10,000 (or 70,000) years.

The cactus is propagated by seeds, cuttings, and grafting. The seeds are naturally dispersed when they are consumed by birds who later excrete them. However, most of these seeds will not germinate as the embryo doesn’t have enough water to use as a fuel source.

The most convenient method of propagation for most cacti is through stem cutting techniques. Cutting are removed by a grower who then treats the cut with chemicals that make the wound anoxic, thus speeding up the healing process. Freshly cut pieces are then grafted onto a host cactus and then later rooted to form new plants.

From the time a plant is harvested to the next cutting, it may have taken as long as 20 years before it can once again be used for propagation.

Pruning

A large, prickly cactus in the Southwest U.S. is known as “Peter Rabbit” because it looks like the iconic children’s character. This is because of the appearance of the spine used to prick people, which is covered by a spiky, red sheath. This plant is called Opuntia microdasys, and it is the culprit of many dog bites.

When dogs run into the spines while digging around in the desert, they can get pricked and cut. If a dog steps directly on one, chances are, it will get severely cut, as well. The cactus will typically have a red spiny sheath, which is its weapon, when it is fully grown. If you look closely at the cactus, you will see that the spines are long and needle thin. When they are at their smallest, they are sharp, and when they are at their largest, they still can cause a problem.

Not only are the spines bad, but the cactus also has a thick, fleshy fruit. When the fruit falls off the cactus, the hard shell will crack. The pulp inside is sweet and is very much like a watermelon. Children are prone to eating the pulp, oblivious to the danger it poses.

Troubleshooting

If you’re gardening in a warm climate, you likely have some prickly types in your garden – or worse, your yard. When you plant a prickly plant, there is a strong chance that you will be pricked or scratched … sometimes more than you would like.

When you have a prickly plant in your garden, you need to look at that plant differently. You need to protect yourself from it. You can start with a simple pair of work gloves. You should also learn how to handle the plant so you can easily take it out of the ground.

Cacti are some of the most prickly plants. Because new cacti plants grow from the center of the stem, you can carefully cut off the top of the cacti. Then you can plant new cacti in pots and move them to their desired spots in the garden.

Another option is to gently groove the buried stem. This will promote new growth around the sides of the groove and prevent new growth from growing from the top of the plant. This is a good idea for several other plants that grow from the center, such as Phlox, hollyhocks, and bleeding hearts.

Growing Problems

It is important to understand that the Prickly Pear does not grow anywhere near as fast as the Echinopsis. The Opuntia Microdasys is a Cacti which grows at a rate of about 2,5cm a year but it will have no branches. The size of the segments increase through the growth and there will be some quite large sizes segments in the stem. A full stem can weigh up to 25 kg.

This is a very well adapted plant from South Africa. It's very cold hardy and will handle a frost season that is about two months long without any issues. You can even go so far as to handle a snow cover and frost in conjunction with a spring frost. This type of plant will usually only grow in the open but being South African it has a fairly high tolerance for sunlight and shade.

A great way to grow this plant is on a long support. This way you will be able to cover this plant when the first frosts. You can then move it outside during the summer. This form of plant will grow much faster than the Opuntia Microdasys as it is more exposed to the sun and is usually laying on a support. Prickly Pear isn't native to Europe, it is from South America.

Pests

One central challenge with raising Opuntia microdasys is overcoming their long list of pests. The most damaging is Opuntia Cactus Beetle, also called the cactus skeletonizer. Though ten or fifteen beetles are unlikely to do lasting damage, it can completely decimate a plant.

To combat the beetle, spiders have been known to predate the beetle before it has a chance to bore into the pad. Also, I’ve found that getting regular rain in the summer, when the beetles are most active, may kill many beetles.

Mealybugs and aphids can be a nuisance if they appear. Cactus thrips are likely to attack the pads as they age, eating the flesh from the pads. Aphids may come to the rescue of the Opuntia cactus in such a scenario. They will attack the cactus thrips as a form of biological control.

The Opuntia cactus is often a predator, or host, to the Opuntia Cactus Rust Mite. They are attracted to the pads and will feed on the bases.

Diseases

Other than being able to fall over from the weight of its own fruit, Opuntia microdasys is not usually afflicted by many problems.

However, the cactus will often succumb to the predations of humans. The ever-resourceful rabbit has come up with one of its most effective schemes, this time to deal with the cactus. The rabbit will pull off a stalk and carefully remove the spines, then push the cactus tip into the ground and nibble off the flesh. The cactus becomes a hollow tube that is both well protected from rain and disease and has just enough nutrients left to give another plant a good start.

FAQs

The Peter Rabbit of cacti is a euphemism for large succulents that people often have in their gardens. The plants are classified as “Woolly Pads”. They have broad, round pads that are less than about five centimeters. Widely varied in size, they are often called candles.

Popular in the 19–20th centuries when rock gardens were popular, they are now seen as old fashioned and are uncommon. The Opuntia microdasys is this style of succulent.

These days, most people prefer them because they like their spiky looks. It is a shame that you must break the stems to increase the size and also because there is a lot of miss information out there.