Introduction

This native is in danger of extinction in Florida (Fig. 1). It forms irregular clumps or shrub-like mounds in sandy soils, and has a very coarse texture. The leaves of prickly pear cactus are inconspicuous, however the plate-like sections of the stem are often thought of as leaves. These plate-like sections are actually modified stems and reach a length of 2 to 6 inches. Stem sections remain green with age and are covered with 3-inch-long spines. Very minute spines (glochids) are located in the numerous areoles. The larger spines are quite painful, however the minute spines cause a lot of irritation if they are captured in clothing or attach to the skin surface.

General Information

Scientific name: Opuntia spinosisima

Pronunciation: oh-PUN-shee-uh spy-noe-SIS-sim-muh

Common name(s): prickly pear cactus

Family: Cactaceae

Plant type: shrub

USDA hardiness zones: 3B through 11 (Fig. 2)

Planting month for zone 7: year round

Planting month for zone 8: year round

Planting month for zone 9: year round

Planting month for zone 10 and 11: year round

Origin: native to Florida

Uses: mass planting; border

Availability: grown in small quantities by a small number of nurseries

Description

Height: 3 to 20 feet

Spread: 3 to 15 feet

Plant habit: spreading; upright

Plant density: open

Growth rate: moderate

Texture: coarse

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: entire

Leaf shape: elliptic (oval)

Leaf venation: none, or difficult to see

Leaf type and persistence: deciduous

Leaf blade length: less than 2 inches

Leaf color: green

Fall color: no fall color change

Fall characteristic: not showy

Flower

Flower color: orange; red; purple; white

Flower characteristic: summer flowering

Fruit

Fruit shape: oval

Fruit length: 1 to 3 inches

Fruit cover: fleshy

Fruit color: red

Fruit characteristic: suited for human consumption; persists on the plant

Trunk and Branches

Trunk/bark/branches: showy; thorns present

Current year stem/twig color: green

Current year stem/twig thickness: very thick

Culture

Light requirement: plant grows in full sun

Soil tolerances: sand; acidic; slightly alkaline; loam

Drought tolerance: high

Soil salt tolerances: good

Plant spacing: 24 to 36 inches

Other

Roots: usually not a problem

Winter interest: no special winter interest

Outstanding plant: plant has outstanding ornamental features and could be planted more

Invasive potential: not known to be invasive

Pest resistance: no serious pests are normally seen on the plant

Use and Management

When the flowers of this plant are produced in large numbers, as on vigorously growing individuals, they put on quite a show. The plant will bloom over a period of several weeks, however the individual flowers only last one day. The flowers are cup-shaped, bright red, appear on the outermost plate-like stem sections, and are 2 to 3 inches wide. The showy berries may reach a length of 2 to 3 inches and are red to purple at maturity (mid to late summer). These fruits may be eaten after the spines and glochids have been singed off with fire, and the seeds of the fruits can be roasted for flour.

These plants are well-suited to hot, dry conditions. Prickly pear cactus can be used as a specimen in areas of a dry, rocky, unirrigated landscape. An established row of these makes an impenetrable border for pedestrians.

This plant is drought, salt, and heat tolerant. It requires a sunny, well-drained site and is tolerant of sandy, alkaline soils. Prickly pear will only tolerate wet conditions for a very short period of time.

Propagation is by division because the seeds of many species are difficult to germinate. The plate-like sections can be placed on slightly moist sand to obtain rooting.

Pests and Diseases

Opuntia spp. have no pests nor diseases of great concern. Root rot can be a problem in wet locations.