Origin
Pediocactus simpsonii (Engelm.) Britt. & Rose var. robustior (Coult.) L. Benson, commonly known as robust pediocactus or Simpson's hedgehog cactus, is a small cactus species native to North America. It is commonly found in the south-western United States, particularly in Utah, Colorado, New Mexico, and Arizona, as well as in northern Mexico.
Common Names
The robust pediocactus is also known by several other common names, including Simpson's hedgehog cactus, Simpson's pincushion cactus, Simpson's ball cactus, and robust hedgehog cactus.
Appearance
The robust pediocactus is a small, clumping cactus that grows to a height of about 3-6 inches. It has a spherical or cylindrical shape with a dense covering of spines that range in color from yellow to brown or reddish-brown. The plant usually produces one or multiple flowers, which are pink, purple or white, during the spring season. The flowers are relatively large, with a diameter of 1.5-2 inches, and have several layers of petals that form a cup shape.
Uses
The robust pediocactus is primarily prized for its ornamental value and is commonly used as a decorative plant in rock gardens, container gardens, and xeriscapes. It is also sometimes grown as a houseplant but requires plenty of sunlight and well-draining soil to thrive. In some Native American cultures, the cactus is used for medicinal purposes, such as treating arthritis and other joint pains. However, these uses are not scientifically proven and should not be relied on as medical treatment.
Growth Conditions for Pediocactus simpsonii var. robustior
Light: Pediocactus simpsonii var. robustior grows well in full sun to partial shade. It requires at least 6 hours of direct sunlight daily for healthy growth. Too much shade can make the plant lanky and weak, while too much direct sunlight can cause scorching of the leaves.
Temperature: This plant can tolerate a wide range of temperatures but grows best in warm to hot temperatures. It can survive temperatures as low as -20°C and as high as 40°C. In the winter, it requires a cooler environment to stimulate growth and flowering in the spring.
Soil: The plant prefers well-drained sandy soil rich in organic matter. It can tolerate various soil types, including sand, gravel, and clay, as long as the soil is well-drained. The soil pH should be between 6.5 and 7.5. It is important to avoid overwatering as excessive moisture can lead to root rot.
Cultivation Methods
Pediocactus simpsonii (Engelm.) Britt. & Rose var. robustior (Coult.) L. Benson is a slow-growing plant that is typically propagated by seed. The seeds can be sown in a well-draining potting mix in the spring or fall. The potting mix should be composed of a blend of coarse sand, perlite, and peat moss. The seeds should be sown on the surface of the soil and lightly covered with additional soil. The pot should be kept in a warm, bright location but out of direct sunlight. Once the seeds have germinated, they should be kept moist, but not waterlogged. As the plant grows, it should be potted up into progressively larger pots to accommodate its increasing size.Watering Needs
Pediocactus simpsonii (Engelm.) Britt. & Rose var. robustior (Coult.) L. Benson is a drought-tolerant plant that prefers dry, well-draining soil. Overwatering can cause the plant to rot, so it is important to allow the soil to dry out completely between waterings. During the plant's active growing season, it may require more frequent watering, but it is still important to avoid overwatering. The best way to water the plant is from the bottom, by placing the pot in a shallow tray filled with water and allowing the soil to absorb the moisture.Fertilization
Pediocactus simpsonii (Engelm.) Britt. & Rose var. robustior (Coult.) L. Benson is a low-maintenance plant that does not require frequent fertilization. However, a balanced, slow-release fertilizer can be applied in the spring to provide nutrients to the plant during its active growing season. It is important to avoid over-fertilization, as this can result in excessive growth and weak stems.Pruning
Pediocactus simpsonii (Engelm.) Britt. & Rose var. robustior (Coult.) L. Benson generally does not require regular pruning. However, if the plant becomes too leggy or develops weak stems, it can be pruned back to encourage bushier growth. It is important to use a clean, sharp pair of scissors or pruning shears to avoid damaging the plant. Any dead or damaged stems should also be pruned away to promote healthy growth.Propagation of Pediocactus simpsonii var. robustior
Pediocactus simpsonii var. robustior can be propagated by seeds or offsets.
Propagation by Seeds
Seeds can be collected from mature fruit capsules that have turned brown. The seeds need to be cleaned and stored in a cool, dry place until ready to plant. It is best to plant the seeds in the fall so that they can experience the winter dormancy period. In the spring, the seeds can be planted in a well-draining soil mix and kept moist until germination occurs.
Propagation by Offsets
Pediocactus simpsonii var. robustior can also produce offsets or "pups" around the base of the parent plant. These can be carefully removed and replanted in a well-draining soil mix. It is important to let the offsets callus for a few days before planting to prevent rotting. The soil should be kept moist but not waterlogged, and the plant should be placed in a location with partial shade until it has established roots.
Disease and Pest Management for Pediocactus simpsonii var. robustior
Pediocactus simpsonii var. robustior is prone to various diseases and pests, which can bring about stunted growth or complete death of the plant. To maintain the health of the plant, the following disease and pest management techniques should be utilized:
Common Diseases
One of the common diseases affecting this plant is root rot caused by fungi such as Phytophthora and Pythium. The disease causes the roots to rot, leading to yellowing, wilting, and dieback of the aerial parts of the plant. The disease mainly thrives in moist soils with poor drainage.
An effective way of controlling root rot is by ensuring adequate drainage in the growing medium and avoiding overwatering. The infected plant should be isolated, and the infected parts removed. The healthy parts of the affected plant can be propagated to create new plants.
Another disease that affects Pediocactus simpsonii var. robustior is bacterial soft rot, which is caused by Erwinia carotovora. The disease causes the formation of soft, water-soaked patches on the plant, rapid wilting, and eventual death. The bacteria mainly spread through contaminated soil, water, and insects.
One way of controlling bacterial soft rot is by ensuring proper sanitation of the growing area, including storage and handling of tools and equipment. It is also important to avoid over-fertilization, which can lead to soft growth susceptible to bacterial infections.
Common Pests
Pests such as spider mites, scale insects, and mealybugs can attack Pediocactus simpsonii var. robustior, causing stunted growth and eventual death. Spider mites mainly cause yellowing and mottled leaves, while scale insects and mealybugs create white waxy secretions on the plant.
To control pests, it is crucial to inspect the plant frequently, especially the undersides of the leaves, for any signs of infestation. Infested plants can be treated with insecticidal soap or neem oil. For severe infestations, it may be necessary to remove the affected parts of the plant or the entire plant and propagate healthy parts.
In conclusion, by implementing proper disease and pest management techniques, Pediocactus simpsonii var. robustior can maintain its health, ensuring that it grows and thrives as intended.
