Cold-Hardy Cactus You Can Grow Almost Anywhere

Several cactus grow wild on the northern Great Plains and into Canada, so if you've written off cold-hardy cactus because your winters hit −20°F, a real palette exists. Prickly pears, spinystar and some hedgehog cactus are hardy to zone 3 or 4; claret cup and cholla to zone 5. They bloom more extravagantly than nearly anything else in the low-water garden, and they ask for two things: full sun and fast drainage.

The same rule applies as for their agave and yucca cousins: winter wet kills hardy cactus, not winter cold. Get the drainage right and zone 4 is easy; skip it and they'll rot even in zone 7.

The 9 at a glance

Zones for the prickly pears come from the Missouri Botanical Garden where rated. For the native ball and hedgehog cactus, which major gardens don't rate, we use conservative figures based on their native range as mapped by the Lady Bird Johnson Wildflower Center.

Prickly pears: the easy ones

1. Plains prickly pear (Opuntia polyacantha)

Zones 4–9 · Water Very low · Size 6–18 in tall, spreading 2–3 ft · Bloom June, yellow, pink or magenta

The native of the shortgrass prairie: low pads, fierce spines and silky flowers. The Wildflower Center maps its range north into Alberta, British Columbia and Saskatchewan. Prickly pear is nearly unkillable in full sun.

Care tip: Handle pads with barbecue tongs; the tiny glochid bristles are worse than the big spines.

2. Brittle prickly pear (Opuntia fragilis)

Zones 3–9 · Water Very low · Size 3–6 in, spreading · Bloom Early summer, pale yellow (often sparse)

The cold-hardiness champion of the prickly pears, rated zones 3–9 by the Missouri Botanical Garden and native from Wisconsin to Washington and into Alberta. Tiny, egg-shaped joints break off easily and root where they land.

Care tip: It blooms sparingly; grow it for form and toughness, not flowers.

3. Eastern prickly pear (Opuntia humifusa)

Zones 4–9 · Water Very low · Size 6–12 in, spreading · Bloom Early summer, yellow

The spreading, nearly spineless prickly pear that even humid-summer gardeners can grow, rated zones 4–9. It still carries glochids, so gloves are a must.

Care tip: Give it sharp drainage; it tolerates more humidity than western species, not wetter soil.

4. Bigroot prickly pear (Opuntia macrorhiza)

Zones 3–9 · Water Very low · Size 6–12 in · Bloom Early summer, yellow with a red center

A Great Plains native with tuberous roots and bicolored flowers, rated zones 3–9 by the Missouri Botanical Garden. Named hybrids, such as 'Coombe's Winter Glow', add bigger flowers and red winter pads for zones 4 and 5.

Care tip: Mass three or five together; a single pad-cluster looks lost.

Hedgehogs, balls and the sculptural crowd

5. Claret cup cactus (Echinocereus triglochidiatus)

Zones 5–9 · Water Very low · Size 6–12 in tall, clumps 1–4 ft wide · Bloom Spring, scarlet

The showpiece: a mound of ribbed stems that disappears under scarlet, hummingbird-pollinated flowers each spring. The Wildflower Center notes that clumps can reach 3 to 4 feet across. Claret cup cactus is native from Colorado to California.

Care tip: Plant it where you'll see it in May; each flower lasts only a few days.

6. Green-flowered hedgehog (Echinocereus viridiflorus)

Zones 4–8 · Water Very low · Size 2–6 in · Bloom Spring, green-yellow, lemon-scented

A small, fist-sized hedgehog with fragrant green flowers, native from southeastern Wyoming and western South Dakota south into Texas.

Care tip: Tuck it between rocks in a rock garden so it doesn't get lost among larger plants.

7. Spinystar (Escobaria vivipara)

Zones 3–8 · Water Very low · Size 2–4 in · Bloom Late spring, bright pink

A golf-ball cactus crowned with pink flowers. The Wildflower Center maps it north into Alberta, Saskatchewan and Manitoba, making it one of the hardiest cactus you can grow. It's perfect for troughs and rock gardens.

Care tip: Top-dress with a collar of gravel so the base never sits in wet soil.

8. Mountain ball cactus (Pediocactus simpsonii)

Zones 4–8 · Water Very low · Size 2–6 in · Bloom Early spring, pink

A high-elevation native of the Rocky Mountains, from southern Montana south to New Mexico. It's one of the first cactus to bloom in spring. It wants gritty scree and cool roots, and it resents summer heat and water at low elevations.

Care tip: Buy nursery-propagated plants only; never collect from the wild.

Cholla: the architectural gamble

9. Cane cholla (Cylindropuntia imbricata)

Zones 5–9 · Water Very low · Size 3–7 ft, tree-like · Bloom Early summer, magenta, then yellow fruit that persists into winter

A spiny, branching silhouette native to southern Colorado, New Mexico and west Texas. Striking, and hardy below zero, but it's heavily armed and sheds joints that root, so plant it well away from paths, pets and anywhere you'll reach with a rake.

Care tip: Wear leather gloves and use long tongs; cholla spines are barbed.

The winter shrivel (don't panic)

Every fall, hardy cactus dehydrate on purpose: pads wrinkle, deflate, flop flat and turn purple-bronze. New growers assume the plant has died and dig up healthy cactus every spring. Less water in the tissue means less ice damage. Leave them alone; they plump back up within weeks of warm weather. A cactus that's soft and black has rotted, almost always from wet soil rather than cold.

How to plant them

1. Full sun, all day. Six hours at minimum; more is better.
2. Mound it and grit it. Raise the bed 8 to 12 inches and mix native soil about half-and-half with coarse sand or fine gravel. No compost (see xeriscape soil prep).
3. Gravel mulch only, an inch or two, tucked under the pads to keep crowns dry (gravel vs. wood mulch).
4. Plant from late spring through midsummer, so roots grow before winter. Water every week or two the first season, then stop; established plants generally need nothing beyond rain, and overwatering is their main enemy.
5. Site them away from roof drip lines and snow piles. Drainage applies to water from above too.

Where they shine

Cactus are the flowering jewels of a rock garden, the tough plants for a hell strip (well back from where people step), and winter structure in zone 5 and zone 6 beds. Mass the prickly pears, put a claret cup where you'll see it bloom in May, and surround everything with cold-hardy succulents that share the same gritty recipe. For inspiration, see desert landscaping ideas; in Colorado's Pikes Peak region, xeriscaping in Colorado Springs covers local conditions.

From our installs

On the Front Range, prickly pears and claret cup are some of our most dependable plants, and they fail for the same two reasons every time: clay that stays wet in winter and wood mulch. We build raised beds of native soil mixed with squeegee or crusher fines, set cactus slightly high, and mulch with gravel. New plants get a deep watering every week or two through their first summer, then nothing after August so they can harden off. Hail bruises pads every few summers; the scars are cosmetic. We keep all spiny plants at least 3 feet from walks and play areas. (Xeris Landscaping is owned by Xeriscaping.com's founder.)

Frequently asked questions

What is the most cold-hardy cactus?

Brittle prickly pear and spinystar are both native into Canada and hardy to zone 3. Bigroot prickly pear is also rated to zone 3.

Do cold-hardy cactus need winter protection?

No covering is needed. Keep them dry: good drainage and no winter watering do more than any cover.

Why is my cactus shriveled in winter?

It's normal. Hardy cactus drain water from their tissue before winter to avoid freeze damage, and they plump back up in spring.

Can I grow cactus in clay soil?

Only if you raise the bed and mix in plenty of grit. Cactus planted directly into flat clay usually rot in the first wet winter.

When is the best time to plant cactus?

Late spring through midsummer, so roots establish in warm soil before winter.