The Surprise Behind Prickly Pear

Lowell Halvorson

In late June, if you drive through the main entrance of the Mt. Cuba Center in Delaware, you’ll pass through some woods and emerge onto a large lawn on both sides of the road. In the distance the Copeland House is at the top of the lawn. Look to your left and a few feet from the edge of the road, you’ll see a bed of Eastern prickly pear (Opuntia humifusa) in full, glorious bloom, situated on the uphill side of a rock outcropping. It’s both surprisingly beautiful and a surprise because you don’t expect cactus as display color. But there it is.

Prickly pear pads with fruit forming.  Photo courtesy of Mt. Cuba.

Surprise and delight is one of the goals of a clever design, and visitors often wander down from the Copeland House to get a closer look. Prickly pear is a complex creature. Stand in front of a planting for a while and try to decode what’s inside it. A sea of large yellow flowers sits on the edge of flattened, upright discs called pads. Mixed among the blooms are emerging buds for future waves of color and the burgundy red fruits from earlier waves. Throughout it all are the signature short sharp spines.

Flowers, pads and buds in detail.  Photo courtesy of Mt. Cuba.

In the center of each flower is a large mass of pollen for the beneficials to enjoy. Try this prickly pear party trick: Use a finger to gently touch the stems and see what happens. If that finger had been an insect, the wiggling stamen would have covered it with pollen to transport to another plant.

Maintaining a bed of opuntia

Technically, a bed of prickly pear is called a colony, and it sustains itself by pads breaking off and rooting into the soil. As prickly pear goes dormant, the pads wrinkle and lie flat in layers, behaving almost like a groundcover. Thick flesh protects the chlorophyll inside, turning a gray-green during the winter, although tints of red and yellow show up occasionally. Hardy down to Zone 4, a colony can have a lifespan of decades. Mt. Cuba’s colony might go back to the ’60s or ’70s, but nobody is sure because the planting predates the entire staff.

Tray of 32 opuntia. Photo courtesy of Pizzo Native Plant Nursery.

Another prickly pear surprise is its widespread status as a native plant. Opuntia humifusa is a native of the Carolina piedmont, the pine barrens of Missouri, the eastern and southern shores of Lake Michigan, and other cactus-y places like Connecticut and Mississippi. When you look at the native databases at the county level, you discover prickly pear is scattered up and down the eastern half of North America.

Eastern prickly pear (Opuntia humifusa) in a landscape bed in Delaware (Zone 7).  Photo courtesy of Mt. Cuba. 

Why? Because it loves sandy soil with pine trees. Opuntia specializes in a common pocket habitat. If you have open pine woods sitting in dry sandy soil nearby you might find some wild prickly pear tucked inside them. Dry, thin soil isn’t a requirement. Opuntia does just fine in standard garden soil, but if you mulch with gravel or have a gravel bed it will excel.

Opuntia’s large, showy spines do hold it back from any serious commercial volume. Watch for the tiny stiff bristles called glochids that can get under the skin and irritate. Trimming the perimeter of a planting is an exercise in not handling the prickly pear. Mt. Cuba’s method consists of using loppers to trim off unwanted pads, then using a grabber-on-a-stick to transfer the loose pads to a bucket. Leather gloves are recommended. Interestingly, even with its aggressive defense, prickly pear still has one predator: the box turtle.

Opuntia growing as a specimen in gravel.  Photo courtesy of Mt. Cuba.

Obviously, a spineless cultivar is needed for any sort of mainstream adoption. Opuntia does have a commercial application in the native and restoration space. It’s a good choice for sandy soils, self-maintains as a colony without spreading and handles drought like a champ. Crews don’t have to return to a site once done. 

Opuntia liners can be sourced commercially. Pizzo Native Plant Nursery sells trays of 32 to wholesale buyers, shipping from late July to early August, and they often have overstock available during those weeks. Their landscape-ready plugs are less prickly to handle and require less labor to install.

Prickly pear in winter. Pads wrinkle up in the cold and the plant becomes prostrate. Photo courtesy of Mt. Cuba.

Another place prickly pear pops up is in the IGCs catering to the avid gardener. I first ran across prickly pear in my neighbor’s front yard, just one of her many unique selections. There’s nothing run-of-the-mill in her collection, proving that retail interest exists for this peculiar plant among passionate gardeners.

A walk through Mt. Cuba generates a lot of good ideas, but not everyone can get over to Delaware. Fortunately, the center populates their Instagram account with visual design concepts generated from their beds. Their website is home to their excellent multi-year trials (mtcubacenter.org) and their newsletter alerts readers of opening blooms as they happen throughout the season. GT

Fairfield, Connecticut, for retail and wholesale horticulture, specializing in business development. He also covers the breeding community for GrowerTalks magazine. You can contact him at (203) 257-9345 or halvorson@triadicon.com.