How to Grow Cactus Plants in Cold-Winter Climates

For gardeners in Northern regions, some plants may feel off-limits—among them, cacti. These desert-dwellers thrive on light, heat, and excellent drainage, which leads many to assume that they can't be grown in cold-weather climates. Though you may think they're limited to the desert Southwest, many cacti varietals are hardy enough to grow deep into Canada. In fact, cactus plants are native only to North and South America.

To successfully grow cacti in a cold-winter climate, it's important to understand how they grow. All cacti are succulents—plants that can store water in their roots, stems, and leaves—but not all succulents are cacti. It's sometimes difficult to tell which succulent is really a cactus, but there's one identifier you can always look for. All cacti (and only cacti) have spine cushions, called areoles, which appear as small bumps on their flesh. These bumps are where spines, branches, leaves, and flowers will eventually grow on the plant.

How to Grow Cacti in Cold-Winter Climates

Cold-hardy cactus plants that grow successfully in northern regions prefer many of the same conditions as their southern counterparts, like ample light. Below you can find some of the most common care requirements for cold-weather cacti.

How to Plant Cacti

Cacti require soil that drains quickly, but you should avoid growing them in pure sand, which doesn't hold enough nutrients for them to thrive. The ideal mixture for growing a cactus is around 40% to 60% coarse sand and up to 10% compost, mixed with traditional garden soil or topsoil for a nutrient-rich, fast-draining mix. You should avoid using fine-grain sand, which can gum up the soil instead of adding drainage. After planting cactus plants, avoid disturbing the soil around their shallow roots. Pea gravel or other small rock mulch prevents soil from blowing away, assists with weed prevention, and keeps the soil temperature even.

Raised beds are recommended to provide excellent drainage. The more rain your area gets, the more drainage you need. In super-wet regions, you should plan to grow cacti in pots under a shelter such as a roof overhang. Likewise, never plant cacti in regular or clay soil as they can easily get too much water and die.

Watering Cacti

Avoid watering cactus in the fall or winter. Cactus plants begin to shrink and take on a wilted, off-color appearance to prepare themselves for the coming weather. This is a normal part of their hibernation process, but if you water them during this time, the excess water can freeze and kill the plant.

When it comes to watering your cacti throughout the rest of the year, the best practice is generally to let Mother Nature do the watering for you. However, if you go for several weeks in hot, dry weather without rain, you can feel free to water your cacti. If the soil is completely dry and the plants look limp or are beginning to droop, they're likely telling you they need water. For best results, saturate the soil thoroughly and avoid pouring water onto the plant directly.

Fertilizing Cacti

Cactus plants grown in the ground don't need much fertilizer—however, they can benefit from spring applications of compost or a liquid fertilizer designed for use on bulbs or vegetables. Avoid fertilizers with a large nitrogen component (the first number of the three shown on the package). Nitrogen causes rapid growth, but the plant may be too tender and become susceptible to winter damage, especially late in the growing season.

Protecting Cactus Plants

It may seem counterintuitive, but cold-hardy cacti can easily survive in areas with plenty of snow. However, in climates that experience harsh winds and temperatures but little snow, cacti can become frostbitten. To prevent damage, carefully cover the plants with burlap as late in the season as possible. The burlap allows the plants to breathe while protecting them from sun, ice, and wind. During warmer winters, carefully place a structure such as a canvas tent over the cactus plants to shelter them from excess moisture.

How to Select Cold-Hardy Cactus Plants

Because of the wide variety of plants within each species, it's a good idea to check the hardiness of a cactus before buying it for outdoor use. The champions of cold-weather cacti come from the prickly pear family, known botanically as Opuntia. Opuntia species come in a wide variety of sizes and shapes, with paddle-like pads and flowers that grow in red, bright pink, or yellow.

There are many kinds of cacti in this family, but two of the toughest are Opuntia fragilis, which is hardy to -58°F, and Opuntia poryapantha, which is hardy to -25°F. The eastern prickly pear (Opuntia compressa), native to most parts of the eastern United States and southern Ontario, is an easy-to-grow choice. Its juicy red fruits (the "pear" of the common name) are edible. Other cactus plants with cold-weather tolerance include:

• Cylindropuntia: Known by the common name cholla, this prickly pear relative grows with segmented cylindrical stems that can reach up to 10 feet tall. Various species have a varied range of hardiness, with many tolerating temperatures down to -30°F.
• Echinocereus: Known as the hedgehog, porcupine, or claret cup cactus, this species grows to be less than a foot tall. They are among the most cold-hardy cacti, with many thriving down to -10°F.
• Escobaria vivipara: Commonly called a pincushion or beehive cactus, this species features squashed spheres or short cylinders with wooly gray stems and grows up to 5 inches tall. It's generally hardy to at least 0°F.
• Corynopuntia (also called Grusonia): Known as the club cholla, this cactus is closely related to the prickly pear and forms a low-growing mat of stems with heavy spines. It's hardy to -10°F.