Overview
Cercidium macrum I.M. Johnston, commonly known as velvet mesquite or mesquite bean tree, is a small to medium-sized tree belonging to the Fabaceae family. It is native to the southwestern United States and Mexico, where it thrives in the arid and semi-arid regions.
Description
The velvet mesquite tree can grow up to 30 feet in height and has a broad, spreading crown and a thick, fissured bark that is light grey in color. The leaves are deciduous, bipinnately divided, and have a fern-like appearance, with small leaflets about 2-5mm long. The flowers are small, yellow, and grow in clusters, appearing in late spring or early summer. The fruit is a long, flat, brown pod, which contains small beans that were used by indigenous people as a food source.
Uses
The velvet mesquite tree has a variety of uses. The bean pods of the tree are edible and nutritious and have a sweet, honey-like flavor when roasted. The beans were a staple food of indigenous people in the Southwest and were also used for medicinal purposes. The wood of the tree is dense and hard, making it ideal for firewood and woodworking. The tree is also used for erosion control, drought-tolerant landscaping, and as a shade tree for livestock. Additionally, because of its ability to fix nitrogen, the velvet mesquite is beneficial to other plants growing in its vicinity.
Cultivation
The velvet mesquite tree is a hardy tree that can tolerate drought and poor soil conditions. It grows best in full sun and well-drained soil and requires little to no irrigation once established. The tree is also tolerant of occasional frost and can grow in temperatures ranging from 20-120°F. The seeds of the tree can be planted directly into the ground and should be watered regularly until established.
In summary, the velvet mesquite tree is a versatile and hardy plant with a range of uses, from food to woodworking and landscaping. Its ability to thrive in arid and semi-arid conditions makes it an important part of the ecology of the Southwest.Light Requirements
Cercidium macrum prefers full sun exposure for optimal growth and development. It thrives in areas with bright and direct sunlight, tolerating some shade during the hottest part of the day. Insufficient light may result in poor growth and stunted development, as well as increased susceptibility to pests and diseases.
Temperature Requirements
The plant is well adapted to hot and dry desert climates, where temperatures can range from 70 to 100 °F. It can tolerate extreme daily temperature fluctuations but prefers to avoid freezing temperatures. The plant may enter dormancy during the winter, shedding its leaves to conserve moisture and energy until favorable growing conditions return.
Soil Requirements
Cercidium macrum grows best in well-draining soils that are sandy, gravelly, or rocky. It can tolerate alkaline soils with a pH of up to 8.5, as well as poor soil fertility and low water availability. However, the plant may suffer from root rot in areas with poorly drained soils or standing water. To promote healthy growth, the soil should be amended with organic matter and watered deeply but infrequently.
Cultivation methods
Cercidium macrum, also known as Palo verde, thrives in hot and dry desert environments. When cultivating the plant, it's essential to ensure the soil is well-draining and rich in organic matter. It's advisable to plant the Palo verde tree in an area with full sun exposure. In addition, the plant is ideal for growing in large pots, making it ideal for those with limited garden space.
Watering needs
Although the Palo verde tree is drought-tolerant, it requires regular watering during its first growing season to promote healthy root growth. Once the tree is established, it requires minimal watering, typically once a month. When watering, it's essential to ensure the soil is moist and not waterlogged, as this could lead to root rot and the eventual death of the plant.
Fertilization
Cercidium macrum requires minimal fertilization, and adding too much fertilizer can result in weak growth and susceptibility to pests and diseases. Applying a balanced fertilizer once or twice a year is sufficient to promote healthy growth and flowering. It's crucial to follow the instructions on the fertilizer packaging and avoid overfeeding the plant.
Pruning
Pruning is essential for maintaining the size and shape of the Palo verde tree and promoting healthy growth. When pruning, it's important to ensure that the cuts are clean and made at a 45-degree angle to minimize the risk of damage and disease. It's advisable to prune the tree during the dormant season to minimize stress on the plant. Younger trees require more frequent pruning to promote healthy growth, while older trees require minimal pruning to maintain their shape.
Propagation of Cercidium macrum I.M. Johnston
The Cercidium macrum I.M. Johnston, known colloquially as the Palo Verde, is a small to medium-sized tree found natively in Southwestern United States and Mexico. It is known for its unique green bark and sparse foliage. Propagating this tree can be done through several methods, including:
Seed Propagation
The most common propagation method for Cercidium macrum is through seed germination. The seeds can be collected from the pods that form after the tree has finished blooming in the spring. Once the pods have browned and dried out, they can be collected and stored in a cool, dry place until planting time. Scarification of the seed coat (such as rubbing with sandpaper) can also aid in the germination process, which can take between 30 to 60 days. The planted seed should be kept consistently moist in a warm, but not hot, environment until it has germinated.
Cuttings Propagation
Another propagation method for Cercidium macrum is through hardwood cuttings taken in the winter. Choose pencil-thick branches from the previous year’s growth, and cut them to approximately 8-10 inches in length. The bottom cut should be just below a node, and the top cut just above a node. Remove any leaves along the bottom half of the cutting and dip the cut end in a rooting hormone. Plant the cutting in a container with well-draining soil and keep in a warm, humid environment until rooted.
Air Layering Propagation
Air layering is a propagation technique that is useful for mature trees that are difficult to propagate through other means. This method involves making a small cut into the bark of a branch and wrapping it with moist sphagnum moss and plastic wrap. Over time, roots will begin to form at the point of injury, which can be cut off and transplanted once they become large enough. This method requires patience, as the process can take several months.
Disease and Pest Management for Cercidium macrum
Like all plants, Cercidium macrum is vulnerable to a range of diseases and pests. Here are some common issues that may affect the plant and effective ways to manage them:
Diseases
Phytophthora Root Rot: This fungal disease attacks the roots of the plant and causes wilting, yellowing of leaves, crown rot, and plant death. To manage the disease:
- Plant Cercidium macrum in well-drained soils.
- Avoid overwatering the plant.
- Remove any infected plant material and debris from around the plant.
- Treat the soil with a fungicide to eliminate the fungus.
Bacterial Leaf Scorch: This bacterial disease causes yellowing, withering, and death of leaves. To manage it:
- Prune and dispose of all affected plant parts.
- Keep the area around the plant weed-free.
- Sanitize pruning tools with alcohol before and after use.
Pests
Nematodes: These worm-like pests attack the roots of Cercidium macrum, leading to stunted growth, yellowing, and plant death. To manage nematodes:
- Plant the tree in soil free from nematodes.
- Mulch the base of the plant with organic matter to discourage nematode growth.
- Avoid overwatering the plant to prevent nematodes from spawning.
- Treat the soil with a nematicide to eradicate existing nematodes in case of infestation.
Aphids: These insects suck sap from plant leaves and cause curling, yellowing, and deformation of leaves. To control Aphid infestation:
- Apply neem oil or insecticidal soap to the plant leaves.
- Introduce ladybugs, lacewings, or other natural predators that feed on aphids.
- Periodically hose down the plant with a strong jet of water to dislodge aphids from the leaves.
By following these tips, you can keep your Cercidium macrum plant healthy and thriving.
