5 Cold Hardy Cactus Species (USDA Zone 4 to 6)

Cacti are known to survive in deserts where conditions are hot and dry. However, there are also species that are well-adapted to cold weather and can withstand frost without damage. These plants remain upbeat even when temperatures fall to -20 degrees Fahrenheit.

Cold hardy cacti have evolved features that help them withstand colder temperatures. Most of them have deep roots, which allow them to access water in the ground even when the surface is frozen. Others have a layer of wax, fluff, or hair covering their stems to help trap some heat.

When choosing a cold hardy cactus you should be aware of poisonous cacti species that can be dangerous to your household members including pets and children. It’s also important to be careful when handling cactus plants with sharp spines. Always use thick leather gloves.

Cold hardy cacti species

The following are cold-tolerant cacti that can be grown in frosty climates (USDA zones 4, 5, or 6).

1. Escobaria

Escobaria is a group of low-growing cacti that are widely distributed in the western US, Canada, and some parts of Mexico. They are popular among enthusiasts due to their attractive color, low maintenance, and cold hardiness. They can tolerate temperatures as low as -20°F (-29°C).

These cacti come in different sizes and shapes, predominantly globose and cylindrical. Their stems are covered in star-shaped tubercles that bear short sharp spines. Escobarias bloom in late spring and summer with yellow, orange, or pink flowers which end in small reddish fruits.

Some of the cold-resistant  species of Escobaria cacti include the following:

• Escobaria leei (Sneed’s pincushion cactus)
• Escobaria missouriensis (Missouri foxtail cactus)
• Escobaria vivipara (Ball Cactus)

You can grow escobaria cacti in a variety of climates without so much demand. They love full sun but they prefer partial shade. Overexposure to direct sunlight can scorch their leaves and cause sunburn. When grown indoors, make sure to place them in a place that receives bright indirect sunlight.

When watering Escobarias, don’t overdo it. Overwatering may cause root rot and other fungal problems. Water them regularly during the growing season, but allow the soil to dry out completely between waterings. When repotting them, make sure to use well-draining soil.

2. Opuntia

Opuntia, commonly known as the prickly pear cactus is a genus of several species known for their tasty fruit. They are among the most diverse cold hardy cacti species cultivated in various parts of the world. Opuntia cacti are also drought tolerant and they can thrive in hot dry conditions.

The Opuntias have flat, oval pads, with some species covered in sharp spines. These cacti bloom in late spring to summer with showy flowers. The flowering is followed by the production of fruits which are edible. Opuntia is also grown in landscapes and homes for as ornamental purposes.

The following are cold-hardy species of opuntia that can be grown in cold climates.

• Opuntia basilaris (Beavertail cactus)
• Opuntia aurea (Coombe’s Winterglow)
• Opuntia debreczyi v. denuda (Potato cactus) 
• Opuntia fragilis (Brittle prickly pear)
• Opuntia humifusa (Eastern prickly pear)
• Opuntia macrocentra (Purple prickly pear)
• Opuntia phaeacantha (Desert prickly pear)
• Opuntia polyacantha (Plains pricklypear)

If you are looking to cultivate opuntia, use well-draining soil and provide it with at least 6 hours of full sun per day. Indoors, place it near the west or south-facing window. This plant is prone to root rot when overwatered, so allow the soil to dry out completely between the waterings.

3. Echinocereus

Echinocereus commonly known as hedgehog cacti is a genus comprising over 50 cacti species native to the southern United States and Mexico. They are usually small ribbed cylindrical plants covered in sharp spines. Echinocereus have small to large, funnel-shaped bright flowers that end in edible fruits.

Several species of the Hedgehog cacti are cold hardy, tolerating temperatures as low as -23°C, but only in dry conditions. They include the following:

• Echinocereus viridiflorus (Nylon Hedgehog cactus)
• Echinocereus coccineus (Strawberry Hedgehog)
• Echinocereus engelmannii (Engelmann’s Hedgehog)
• Echinocereus fendleri (Fendler’s Hedgehog)
• Echinocereus lloydii (Lloyd’s Hedgehog)
• Echinocereus triglochidiatus (Kingcup cactus)

Echinocereus cacti are beautiful and easy to care for, which makes them popular ornamental plants in homes and gardens. Their flowers and fruits are often used in salads or desserts as well. So you can grow them indoors for both culinary and beauty reasons.

These cacti prefer full sun and well-draining soil. When growing them indoors, use succulent mix and a pot that has drainage holes. Watering should be regular during the summer but the soil should be allowed to dry completely before watering again.

4. Cylindropuntia

Cylindropuntia also called the chollas are a group of cacti plants native to northern Mexico and the Southwestern US. They are known for their barbed spines that firmly attach to the skin, animal fur, and clothing. While they are typical desert plants, some species can withstand freezing temperatures.

Some of the cold hardy Cylindropuntia cacti species include the following:

• Cylindropuntia leptocaulis (desert Christmas cactus)
• Cylindropuntia davisii (Davis Cholla)
• Cylindropuntia imbricata (Tree Cholla)
• Cylindropuntia kleiniae (Pencil Cholla)
• Cylindropuntia spinosior (Walking Stick Cholla)
• Cylindropuntia whipplei (Whipple or Plateau Cholla)
• Grusonia clavata (Club Cholla)

Chollas are not typically grown as houseplants perhaps due to their dangerous spines. However, they can be grown outdoors in warm, dry, or cold climates. They prefer full sun and well-draining soil. They should be watered regularly during the summer but the soil should be allowed to dry out completely.

5. Pediocactus simpsonii 

Pediocactus simpsonii also known as the Mountain Ball Cactus or Simpson’s hedgehog cactus is a small ball-shaped plant in the small Pediocactus genus. It is native to the western United States and Mexico. It is a cold-hardy cactus, and it can survive temperatures as low as -20 degrees Fahrenheit.

Simpson’s hedgehog cactus is typically a slow-growing plant that can take many years to reach maturity. The stem is densely covered in spines. This plant blooms in late spring with yellow, white, or pink flowers. Pediocactus simpsonii is easy to care for and can make a beautiful indoor cactus.

If you are interested in cultivating this cactus, plant it in well-draining soil and place it in a spot where it will receive at least 6 hours of direct sunlight per day. Watering should be done regularly in spring and summer but the soil should be allowed to dry completely between the waterings.

Final Thought

Most cold hardy cacti originate at high altitude areas, where the temperatures are cooler. They have special adaptation features that make them able to withstand frosty conditions. Like any other cacti, most cold hardy cacti prefer full sun, well-draining soil, and typically dry air with less humidity. The plants should also be inspected regularly for pests and other problems.