A cactus plant needs low to medium light and a porous yet moisture-retentive compost. It will benefit from a weekly misting in spring to encourage bud formation.
When buying a cactus plant, look for one with healthy spines and no signs of bruising or lopsided growth. It should also be planted as it was originally positioned, as it will not thrive if covered with soil.
1. Saguaro Cactus (Carnegiea gigantea)
The saguaro is the state symbol of Arizona. Its spines protect the cactus from hungry animals, and its outer layer acts like leaves by absorbing sunlight and catching rainwater. The saguaro blooms in May and June, attracting pollinators such as birds and bats. These creatures play an important role in helping the saguaro to grow and produce fruit, according to Tohono O’odham creation stories.
Saguaros can be extremely large. They are able to store water in their spines, which are actually ridged pleats that allow the plant to expand without stretching or bursting. The saguaro’s skin also acts as a barrier, restricting the flow of water through its stomates and preventing excessive water loss. This adaptation allows the saguaro to survive in the rocky Sonoran Desert of Arizona, southeastern California, and northern Mexico. The saguaro’s scientific name—Carnegiea gigantea—is named for industrialist and philanthropist Andrew Carnegie, who helped establish the Desert Botanical Garden in Tucson, Arizona, in 1903. It is an iconic part of the Southwest landscape.
2. Sempervivum (Sempervivum sempervirens)
Sempervivums are rock garden staples and are hardy enough to grow in many climates. They are tolerant of the cold and often flower in summer producing pink or purple bracts that can last several weeks.
These succulents grow as mat-forming clumps of rosettes. The mother rosette will spread in all directions producing offsets (hens) that are hermaphrodite and eventually develop flowers of varying colours. After flowering the hen dies, leaving behind many young offsets that will continue to grow.
Unlike some other succulents, Sempervivums thrive in bright conditions and can be used indoors as well as outdoors. Water them sparingly and allow the majority of the soil to dry out in between – especially in winter! Fertilise with a ‘Cactus’ feed at fortnightly intervals throughout the year. Avoid allowing excess moisture to settle in the crown or underneath the plant as this can cause southern blight or black root rot.
3. Prickly Pear Cactus (Opuntia sempervirens)
The prickly pear cactus is one of the most familiar and distinctive cacti. It is native to the Western Hemisphere, and its flowers and fruit are a favorite food for bees and other wildlife. Its pad stems are covered in spines and glochids, which protect it from predators.
Its pads and fruits are edible, but only after removing the spines and glochids. They can be boiled or grilled, made into juice or jams, and eaten raw in salads. Some species have been found to reduce blood sugar levels in diabetics, and they also contain high amounts of fiber and anti-oxidants.
The prickly pear was first brought to Europe by explorers, and it has since become established in many areas where it is not native. Phil Hardberger Park’s prickly pear plants include the Plains Prickly Pear (Opuntia macrorhiza), which is the State Plant of Texas.
4. Bonsai Cactus (Cactus sempervirens)
Cacti are the perfect low-maintenance plants for indoor gardening. Bonsai is a traditional practice in which the shapes and forms of plants are manipulated to create miniature landscapes. By combining cacti with rocks, sand and gravel(or lava rock), you can create unique one-of-a-kind living sculptures.
Unlike other plant species, cacti do not have broad leaves, instead they have specialized pads (or stems) that have scales and spines. These pads allow cacti to catch more sunlight and absorb water.
When planting a cactus, you should use a special potting soil designed for this type of plant. A good quality soil will include a lot of sand and other materials that mimic a cactus’ natural dry environment. Also, when repotting, be careful to remove the old soil without damaging the cactus. Afterwards, trim any roots that are matted and dead.
5. Pachycereus (Pachycereus sempervirens)
The Pachycereus genus is characterized by large, columnar cacti with thin stems and sparse spines. This genus is native to the Sonoran Desert in Mexico and California. Many species within the genus can grow to heights of more than 60 feet. The fruit of this genus is edible and is used in traditional Mexican cuisine.
These cacti are also popular in gardens and landscapes, as they can be grown to create dramatic focal points in the garden or landscape. They require full sun and well-draining soil, but are tolerant of drought conditions.
From an ecological standpoint, Pachycereus cacti play a critical role in arid ecosystems by stabilizing sandy or rocky soils and preventing erosion. They also provide shelter and habitat for a variety of animals. In addition, they are a source of food for birds and insects.
6. Prickly Pear Cactus (Opuntia sempervirens)
This genus is one of the most well-known and diverse cacti, with many species having been cultivated for food in many countries. The pads (cactus stems), or nopales, and fruits of opuntia are eaten raw or cooked and used in dishes such as tacos and soups. The spines must be removed from the pads before eating.
The Coastal Plain has two prickly pear species with large, flat, green pads: Southeastern prickly pear, O. engelmannii, and Common or Eastern prickly pear, O. mesacantha var. mesacantha and O. humifusa. They are commonly found in sandy roadsides, clearings, and sand hills.
Both species have flat pads with air pores called areoles that form clusters of barbed prickles. The pads are eaten raw or cooked, including in some Mexican dishes such as salsa and tacos. In addition, the fruit is relished by arid-land animals such as the prickly pear island snail and Cyclura rock iguana. The fruit contains a natural red dye, cochineal, produced by a tiny insect, Dactylopius coccus.
7. Prickly Pear Cactus (Opuntia sempervirens)
The prickly pear is a symbol of Mexico and the Southwest. This genus (Opuntia) has a number of species with flat pads, called nopales in Spanish, that look like leaves and serve several functions including water storage and photosynthesis. Some have defensive spines that menacingly grow out of the pads, providing fodder for rural Southwestern family folklore. Fortunately, there are also spineless varieties.
Cacti in this genus are very well adapted to dry climates and require a sunny site with well-draining soil. They can withstand heat and drought but benefit from supplemental irrigation during the summer. An established row of prickly pear cactus forms a natural barrier for pedestrian traffic in hot, rocky or seaside locations. They are susceptible to cochineal scale and may need insecticide application. This cactus is very popular with gardeners because of its attractive form and color.
8. Prickly Pear Cactus (Opuntia sempervirens)
As their name suggests, prickly pear cacti are critical members of arid-land ecosystems. They provide food for tortoises, iguanas, rabbits, deer and peccaries. They offer shade and shelter for reptiles including cactus wrens, as well as for many species of birds, who spread the seeds. They also are a host plant for the fungus Saccharomyces cerevisiae.
In Latin countries, prickly pear plants are cultivated for their pads (called nopales) and fruit. These are often de-spined and used like a vegetable, with their mucilaginous texture similar to okra or green beans. In addition, the cactus fruits are eaten raw, and flower petals can be added to salads.
Phil Hardberger Park features several prickly pear plants along its trails. It’s easy to propagate these from stem segments, which will root in sand or other loose soil. This cactus is very heat and drought tolerant.
9. Prickly Pear Cactus (Opuntia sempervirens)
Phil Hardberger Park is home to a wide variety of Prickly Pear, the State Cactus of Texas. Three very similar species are found in Virginia, including Southeastern prickly pear (Opuntia mesacantha var. lindheimeri) and Common or Eastern prickly pear (Opuntia humifusa). All of them have flat evergreen stems.
Each prickly pear pad has numerous air holes called areoles. These are lined with tiny spines called glochids that can irritate the skin. When handling a prickly pear, wear thick gloves or use an old towel folded into several layers.
The pads bear round, ripe fruit that ranges in color from green to red to orange shades. The fruit is used for food and beverages, such as cactus juice. The plant is adapted to hot, dry environments and grows in rocky and sandy places. It has become invasive in some places. It establishes complex ecological interactions with native species such as ants and vervet monkeys, and with the introduced moth Cactoblastis cactorum.
10. Prickly Pear Cactus (Opuntia sempervirens)
This cactus grows flat, paddle-shaped pads called cladodes that are green to blue-green and often crowned with spiny spines. These spines are surrounded by hairlike prickles that readily adhere to skin or clothing and can cause itching. These prickles are called glochids.
The prickly pear (Opuntia sempervirens) is native to desert regions of Mexico and the American Southwest. These cactuses are commonly known for their pretty flowers that contrast with their unfriendly-looking spines.
This cactus is drought tolerant and prefers full sun and well-draining soil. It is susceptible to cochineal scale, which appears as a white, cottony tuft on the plant. Hose off infected plants with a hard stream of water to control this pest. This cactus is also susceptible to frost damage. Prune diseased or damaged pads in the summer. This cactus produces yellow flowers and ripe fruit, which are a rich red color.
