Origin and Common Names
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. is a species of cactus native to North America, primarily found in the western United States, Canada, and northern Mexico. It is commonly known as Mojave prickly pear or Snake River cactus.Appearance
Mojave prickly pear cactus grows in clumps or patches and can reach a height of up to 3 feet. It has flat, fleshy pads covered in small, hair-like spines that can easily detach upon contact, called glochids. These spines help to deter herbivores and protect the cactus from predators. The fruit of the cactus is oblong and green, turning a reddish-purple when ripe. The fruit is edible and has been used by indigenous peoples for its nutritional and medicinal properties.Uses
Mojave prickly pear cactus has several uses, including ornamental and medicinal. It is commonly used in xeriscaping, a landscaping technique that focuses on using drought-resistant plants in arid environments. The cactus is also used for its medicinal properties, including treating wounds, reducing inflammation, and lowering blood sugar levels. The fruit of the cactus, also known as tunas, is edible and can be eaten fresh or used to make jams, jellies, and candies. The pads of the cactus, known as nopales, are also edible and can be used in a variety of dishes, including salads, stews, and tacos. In conclusion, Mojave prickly pear cactus is a unique and versatile plant species that has a significant impact on the environment and human health. It is known for its ornamental value, as well as its nutritional and medicinal properties, making it a valuable addition to any garden or natural landscape.Light Requirements
The plant Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. prefers bright to full sunlight. It can grow well in direct sunlight, making it an ideal sun-loving cactus. However, it is best to provide some protection from excessive sun exposure during the hottest part of the day, especially in the summer months, to avoid sunscald.
Temperature Requirements
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. grows well in warm temperatures and can tolerate a wide range of temperatures. It is hardy to USDA zones 5 to 9 and can withstand temperatures as low as -20°F (-29°C). However, for optimal growth, it is best to keep the plant in a temperature range between 60°F to 90°F (15°C to 32°C). Avoid exposing the plant to freezing temperatures for extended periods.
Soil Requirements
The Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. grows well in well-draining soil. It can tolerate a wide range of soil types, including sandy, loamy, and rocky soils. However, it prefers slightly sandy or rocky soils with low to moderate fertility levels. The soil pH should be slightly acidic to neutral, with a range of 5.5 to 7.0. Try to avoid waterlogged soils, which can cause root rot.
Cultivation:
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. can be propagated through seeds and cuttings. It can be grown in well-draining soil with a pH range of 6.0-7.5. The plant requires full sunlight for at least six hours a day and can tolerate hot and dry conditions. It grows well in USDA hardiness zones 4-9 and can be grown indoors in containers as well.
Watering needs:
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. is drought-tolerant and does not require frequent watering. It is best to water the plant only when the soil is completely dry, and water should be provided in small quantities. Over-watering can lead to root rot and damage the plant.
Fertilization:
The plant does not require frequent fertilization. Fertilization can be provided once a year during the growing season using a balanced fertilizer. It should be applied in small quantities and should not be overdone. The plant can also benefit from the addition of organic matter to the soil.
Pruning:
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. does not require frequent pruning. However, it is recommended to remove any diseased, damaged, or dead parts of the plant. Pruning can be carried out during a dormant period, preferably in late winter or early spring, before the start of the growing season. It is also essential to wear gloves and use a clean, sharp tool while pruning as the spines can cause injury.
Propagation of Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult.
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult., commonly known as Plains pricklypear, can be propagated through various methods. Some of the common methods are:
Seeds
The easiest and most common way to propagate Opuntia polyacantha is by using its seeds. The seeds can be collected from the ripe fruit, which usually appears in late summer or early fall. The collected seeds can be stored for several years before use. Before sowing, the seeds can be soaked in room temperature water overnight to aid germination. Sow the seeds in well-draining soil mix, maintaining a suitable temperature, until germination occurs.
Stem Cuttings
Another effective method of propagating Opuntia polyacantha is through stem cuttings. The cuttings should be taken from healthy and mature plants during the growing season. Cut sections of about 6 inches, remove the bottom spines, and allow the cutting to callus over for a few days. After this, plant the cutting in a well-drained soil mix, keeping it moist. Within a few weeks, the cutting will start developing new roots.
Grafting
Grafting is also a useful method for propagation, especially for delicate or larger specimens, or when the cultivar isn't likely to root on its own roots. For Opuntia polyacantha var. 'Trichophora', grafting is normally chosen because it has complex roots that are prone to damage, and it has specialized adaptations to resist cold weather which are easier to maintain when the plant is grafted on rootstock.
It's best to use sacrificial rootstocks that are known to successfully allow the scion to survive. To begin, choose a healthy and strong rootstock; then remove its spines and slice the stem in two. You must match the diameter of the stock with the scion. After matching the slice, interlock both pieces, binding them together with string or other non-toxic ties. The graft should be grown in a well-drained soil mix and should be kept moist.
Disease Management
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. can be affected by various diseases that can damage the plant's health and reduce its yield. The following are some common diseases that might affect the plant and ways to manage them:
Bacterial Soft Rot
Bacterial soft rot is caused by Erwinia carotovora and occurs during warm, wet weather. It causes plants to wilt and decay, eventually dying. To manage this disease, plants should be well-spaced, and any diseased plants should be removed and destroyed. Spraying with copper-based fungicides also helps.
Fungal Rot
Fungal rot is caused by various fungi, including Fusarium oxysporum and Rhizoctonia solani. It causes yellowing of the plant, wilting, and dieback. To manage this disease, adequate plant spacing, good drainage, and optimal moisture conditions should be ensured. Diseased plants should be removed and destroyed. Fungicides containing azoxystrobin or fludioxonil can also be applied to control the spread of the disease.
Pest Management
Opuntia polyacantha Haw. var. trichophora (Engelm. & Bigelow) Coult. can also be affected by various pests that can damage the plant's health and yield. The following are some common pests that might affect the plant and ways to manage them:
Cactus Moth
The cactus moth, Cactoblastis cactorum, lays eggs on cacti, which upon hatching, larvae burrow into the pads and cause devastating damage. To manage this pest, the pads should be inspected regularly, and any eggs or larvae visible should be removed. The introduction of natural predators, such as parasitic wasps, can also help control the spread of the pest.
Prickly Pear Mealybug
The prickly pear mealybug, Hypogeococcus pungens, causes white masses to form on the cacti pads. It reduces the plant's vigor and can cause its eventual death. To control the spread of this pest, systemic insecticides containing imidacloprid and dinotefuran can be applied. The introduction of predator insects, such as Cryptolaemus montrouzieri, can also help to control its spread.
