Origin and Common Names
Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles, commonly known as New Mexico locust, is a small deciduous tree that is native to the southwestern United States, mainly in Arizona, New Mexico, and Texas. It belongs to the Fabaceae family, which also includes peas, beans, and other legumes.Appearance
The New Mexico locust tree has a dense, spreading crown with a height of up to 25 feet and a width of up to 20 feet. The bark is smooth and grayish-brown, with prominent ridges and furrows as the tree ages. The leaves are pinnately compound, with five to seven oval leaflets that are bluish-green and slightly hairy on the underside. The flowers are fragrant and appear in late spring or early summer, in clusters of 3-10 on the branches and sometimes on the trunk. They are pinkish-purple to lavender and shaped like a pea flower. The fruit is a flat seed pod, about 2-3 inches long, and turns from green to brown as it ripens in late summer or early fall.Uses
The New Mexico locust tree has several uses, including as an ornamental tree for landscaping, especially in xeric gardens. It is drought-tolerant, disease-resistant, and does well in hot, dry climates. The sapwood and heartwood are pale-yellowish to light-brown and are used for fence posts, fuelwood, and charcoal. The bark has been used to make a yellow dye, and the flowers are a source of nectar for bees and other pollinators. The plant has also been used for traditional medicine by indigenous people to treat a variety of ailments, including stomach problems, cough, and fever. However, it should not be consumed without the guidance of a medical professional, as it may also have toxic effects.Light Requirements
The Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles requires full sun exposure to grow and develop optimally. It thrives in areas with direct sunlight for at least six hours a day. Hence, it is not suitable for areas with partial or full shade as it may affect its overall growth and development.
Temperature Requirements
The plant is also highly adaptable to various temperature ranges. It thrives well in warm climates with daytime temperatures ranging between 70 to 85 degrees Fahrenheit and nighttime temperatures around 50 to 60 degrees Fahrenheit.
However, this species can also tolerate cold temperatures as low as -20 degrees Fahrenheit, making it adaptable to almost all climatic regions.
Soil Requirements
The Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles prefers well-draining soils that are moderately moist. However, it can also grow well in areas with low moisture conditions, such as deserts. The plant can tolerate occasional flooding and also requires soils with a pH around 7.0 to grow optimally.
Furthermore, it can grow in sandy and rocky soils, but it requires a good organic matter, ensuring excellent drainage and enough nutrients to support its growth.
Cultivation Methods
Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles, commonly known as New Mexican locust, can grow in a wide range of soils, including loamy, sandy, and gravely soils. The plant prefers a well-drained soil in full sunlight to partial shade. The seed should be sown in spring, early summer, or fall, directly into the soil about 3 cm deep.
Watering Needs
New Mexican locusts require moderate watering. It is recommended to water the plant regularly during the first year after planting to ensure root establishment. Once established, the plant can tolerate drought conditions. During prolonged drought periods, deep watering should be done about once a week.
Fertilization
The New Mexican locust can tolerate poor soils and thus require little or no fertilization. However, adding compost to the soil before planting can promote healthy growth. The plant can also be fertilized with a balanced fertilizer in early spring, once per year.
Pruning
Pruning should be done during winter dormancy. The plant should be pruned to remove any dead, diseased, or damaged branches. Pruning can also promote dense growth and increase the number of blooms. The plant should not be over-pruned. Only a third of the total growth should be removed at a time.
Propagation of Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles Plant
Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles is propagated by various methods. Following are the different propagation methods for this plant:
Seed Propagation:
Seeds are the primary method for propagating Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles plant. The seeds should be collected during the fall season when the pod turns brown. The seeds should be sown in a container or directly in the ground, depending on the environmental requirements, during the early spring season. Seeds should be planted in well-drained soil and watered regularly. Once seedlings are 4-8 inches tall, they can be transplanted to permanent locations.
Cuttings Propagation:
Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles plant can also be propagated through softwood cuttings. Take young branches during the early summer season and cut them into 6-inch lengths. Remove the leaves from the lower half of the cutting, dip the cutting's end in rooting hormone powder, and plant it directly in a well-drained propagation medium. Keep the container covered with a plastic bag with holes for air circulation and misting. After roots have formed, the cutting can be transplanted to a larger container or directly in the ground.
Division Propagation:
Division can be used to propagate Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles plant if there are many stems or the main plant is very large. Dig up the plant during the dormant season, separate the roots into smaller clusters using a sharp knife or shears, and plant each cluster in a well-prepared hole in the ground, or in a container. Water the plant regularly, when the soil dries, and provide a suitable growing environment.
Disease Management
Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles is susceptible to a range of diseases that can damage or kill the plant. Common diseases observed in this plant include:
- Crown rot: Caused by the fungus Phytophthora cinnamomi, this disease causes yellowing and wilting of leaves, stunted growth, and ultimately plant death. To manage this disease, avoid planting in poorly drained soils and remove infected plants to avoid spreading the fungus.
- Leaf spot: This disease is caused by the fungus Phyllosticta robiniae and appears as small, dark spots on the leaves. To manage this disease, remove infected leaves and improve air circulation around the plant.
- Powdery mildew: This fungal disease causes a white, powdery coating on the leaves. To manage this disease, improve air circulation around the plant and remove infected leaves.
- Root rot: This disease is caused by the fungus Phytophthora spp. and causes roots to rot, leading to wilting and ultimately plant death. To manage root rot, avoid planting in poorly drained soils and ensure proper soil drainage.
Pest Management
Robinia neomexicana Gray var. subvelutina (Rydb.) Kearney & Peebles is also susceptible to a range of pests that can cause significant damage. Common pests observed in this plant include:
- Aphids: Aphids suck the sap from the leaves, causing them to curl and twist. They also excrete a sticky substance called honeydew, which can attract other pests and lead to fungal diseases. To manage aphids, spray the plant with a strong blast of water or apply an insecticidal soap.
- Leafhoppers: Leafhoppers are small, winged insects that suck the sap from the leaves. They can cause significant damage, including yellowing and wilting of leaves. To manage leafhoppers, remove any weeds in the vicinity of the plant, which can serve as a breeding ground for the pest, and apply an insecticidal soap.
- Thrips: Thrips are tiny insects that can cause significant damage, including distorted or discolored leaves and stunted growth. To manage thrips, apply an insecticidal soap or neem oil.
