Plant Description
Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer, commonly known as the Santa Cruz island buckthorn, is a small tree or evergreen shrub that belongs to the Rhamnaceae family. This plant is endemic to Santa Cruz Island, California, and is characterized by its oval-shaped leaves and small white or green flowers.
General Appearance
The Santa Cruz island buckthorn typically grows up to six feet in height, with a spread of three to four feet. The tree has a slender trunk and branches that are covered with a smooth, reddish-brown bark. The leaves are glossy, dark green, and range from one to four inches in length. The undersides of the leaves are covered in a light-colored, soft fuzz, which gives the plant its tomentella name.
Common Name
The Santa Cruz island buckthorn is commonly known as tomentella or Santa Cruz island buckthorn. It is also referred to as “hedge nettle” due to the plant’s historical use as a substitute for nettle in making twine.
Uses
The Santa Cruz island buckthorn has long been used by indigenous peoples for a variety of medicinal purposes. The plant’s bark, leaves, and roots contain compounds that have been used to treat ailments such as stomach pain, fever, and skin disorders. The plant is also used as an ornamental plant for landscaping purposes, due to its attractive appearance and drought tolerance. However, it is important to note that the plant is toxic to livestock and should not be consumed by animals.
Growth Conditions for Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer
Light: Rhamnus tomentella Benth. ssp. crassifolia grows best in moderately shaded to shaded areas. It can tolerate partial sun in cooler coastal orientations, but excess sun can cause leaf burn.
Temperature: The plant is a native of Mediterranean-climate regions. It thrives in cool, mild winters and dry summers. The plant is well-suited to USDA Hardiness Zones 7a through 10b and will grow in mildly snow-inclined and heavily sunny areas.
Soil: Rhamnus tomentella Benth. ssp. crassifolia is well-acclimatized to poor, rocky soil, especially when it is well-drained and with a pH range of 5.5 to 8.0. In sandy or low-rainfall areas, the plant prefers soil with medium moisture retention. Adequate underground aeration and drainage are crucial for the plant's health. It does not prefer compacted or clayey soils.
Cultivation Methods for Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer
Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer is a slow-growing and shrubby plant native to California. It prefers well-drained soils and requires full sun to partial shade to grow. If you want to grow this plant in your garden, you must follow specific cultivation measures to maintain its health and beauty.
The ideal time to plant Rhamnus tomentella Benth. ssp. crassifolia is in late winter or early spring. Ensure that the soil is well-drained and deeply worked before planting the plant. As the plant is small, space it apart from other plants to ensure its growth is not impeded by competing plants.
Watering Needs for Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer
Watering Rhamnus tomentella is quite crucial as the plant needs moderate amounts of water to grow. You should not overwater the plant as it is prone to waterlogging, which might lead to root rot. A deep watering every week is sufficient, while in hot weather, the plant may require watering every other day. Watering should be done at the base of the plant avoiding the foliage to prevent disease and pest infestation.
Fertilization of Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer
Rhamnus tomentella Benth. ssp. crassifolia prefers a nutrient-rich soil for healthy growth. As the soil gets depleted over time, you need to fertilize the plant. You should fertilize this plant in late winter as it starts to grow. Use a balanced fertilizer to get the best results, and apply following instructions on the manufacturer label. Over-fertilization should be avoided, which can cause irreparable damage to the plant.
Pruning of Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer
Pruning is necessary for the healthy growth of Rhamnus tomentella Benth. ssp. crassifolia. However, avoid over-pruning as this can cause irreversible damage. Ideally, prune the plant after blooming or during winter dormancy. Pruning is done by cutting back old or damaged branches and reducing the size of the plant to maintain an appealing shape. Additionally, pruning can help prevent disease by allowing good air circulation and reducing overcrowding.
Propagation of Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer
Rhamnus tomentella Benth. ssp. crassifolia (Jepson) J.O. Sayer, commonly known as 'Santa Cruz Island Buckthorn,' is a native plant to California, USA. It is a slow-growing shrub typically found in coastal areas and chaparral habitats. Propagation of this plant can be done using various methods.
Seed propagation
The easiest and most common method of propagating Rhamnus tomentella Benth. ssp. crassifolia is by seed. Collect seeds when the fruit is ripe, typically during September to October. Separate the seeds from the fruit pulp, and air dry them for a few days. Sow the seeds in well-draining soil, and water regularly to maintain moisture. Germination may take up to 12 months, so patience is necessary. Once the seedlings reach 3-4 inches in height, they can be transplanted to their permanent location.
Cuttings propagation
Rhamnus tomentella Benth. ssp. crassifolia can also be propagated through stem cuttings. Take cuttings in early summer when the plant is actively growing. Cut a 6-inch stem section just below a leaf, remove the leaves from the lower half of the stem, and dip the cut end in rooting hormone. Plant the cuttings in well-draining soil, and keep them moist by covering them with a plastic bag. Rooting should occur within 4-6 weeks, and once rooted, the new plants can be transplanted.
Layering propagation
Layering propagation is another method of propagating Rhamnus tomentella Benth. ssp. crassifolia. In this method, peg down a low-growing stem onto the soil surface and cover it with soil and mulch. Let it grow for several months, and once roots have formed, cut the rooted stem from the parent plant, and transplant it to a permanent location.
Propagation of Rhamnus tomentella Benth. ssp. crassifolia can be done through seed, cuttings, or layering. Each technique has its advantages and disadvantages, and it depends on the grower on which method to use.
Disease Management
Plant diseases can greatly affect the health and growth of Rhamnus tomentella Benth. ssp. crassifolia. Below are some common diseases that affect the plant and ways to manage them:
Anthracnose
This fungal disease causes irregular-shaped brown spots on the leaves that later progress to the stem and branches. To manage the disease, it is important to keep the plant healthy through regular watering, pruning, and fertilization. Fungicides can also be used.
Crown gall
Crown gall is caused by bacteria that create galls on the stem. To manage this disease, it is best to remove the infected plant and replant with healthy stock. Avoid injuring the plant and keep it healthy and stress-free.
Phytophthora root rot
This fungal disease attacks the root system of the plant, leading to wilting and stunted growth. To manage the disease, avoid overwatering and ensure good drainage. Fungicides can also be used.
Pest Management
Several pests can cause damage to Rhamnus tomentella Benth. ssp. crassifolia. Below are some common pests that affect the plant and ways to manage them:
Aphids
Aphids can be controlled through the use of predator insects like ladybugs and lacewings. Alternatively, insecticidal soap or neem oil can be used.
Spider mites
Spider mites can be managed by spraying the plant with water to wash off the pests or using insecticidal soap or neem oil. Predatory mites can also be used to control the population.
Scale insects
To control scale insects, they can be removed from the plant with a cotton swab dipped in alcohol or neem oil. Alternatively, insecticidal soap or neem oil can be used. Regular pruning and maintenance of the plant can also prevent infestation.
