Overview of Rubus ulmifolius Schott var. inermis (Willd.) Focke
Rubus ulmifolius Schott var. inermis (Willd.) Focke is a perennial plant belonging to the Rosaceae family. It is commonly known as Thornless Elm-leaved Blackberry, Thornless Evergreen Blackberry, and Thornless Himalayan Blackberry. The plant is native to Europe and western Asia and was introduced to North America in the late 1800s.
General Appearance of Rubus ulmifolius Schott var. inermis (Willd.) Focke
Rubus ulmifolius Schott var. inermis (Willd.) Focke has a sprawling and spreading growth habit. It can grow up to 10 feet in length and 3-6 feet in height. The plant has long arching canes that are green and glabrous, meaning they are smooth and free from hair or bristles. The leaves are dark green, toothed, and have a three-lobed shape similar to elm leaves. The flowers are pinkish-white and bloom in late spring to early summer. The fruit is a blackberry that is edible and sweet, with a tart flavor.
Uses of Rubus ulmifolius Schott var. inermis (Willd.) Focke
Rubus ulmifolius Schott var. inermis (Willd.) Focke has several uses. The plant is cultivated commercially for its fruit, which is used to make jams, jellies, pies, and other desserts. The leaves of the plant have medicinal properties and are used to treat digestive problems, sore throats, and menstrual cramps. The plant is also used for erosion control and as a groundcover due to its spreading growth habit. Additionally, the plant provides habitat for birds and other wildlife.
Light Requirements
Rubus ulmifolius var. inermis thrives in full sunlight to partial shade. It can tolerate shade but may not produce as many fruits. Therefore, it is best to plant this species in areas exposed to direct sunlight or in locations that receive about 6 hours of direct sunlight.
Temperature Requirements
The plant can be grown in various temperature zones, including USDA hardiness zones 6 to 9. However, the ideal temperature ranges from 18 to 24 °C (64.4 to 75.2 °F). Temperatures above 30°C (86°F) can reduce the quality and quantity of fruit produced. Additionally, Rubus ulmifolius var. inermis can tolerate low temperatures during winter and goes dormant when temperatures drop below -14°C (7°F).
Soil Requirements
Rubus ulmifolius var. inermis requires well-drained soils that are rich in organic matter. The plants can tolerate a wide range of soil types, including loam, sandy, or clay soils. However, the pH level should be between 5.5 to 7.0; acidic soils can cause root damage, while alkaline soils can affect plant growth. The soil should also be moist but not waterlogged, especially during the growing season, but it should be allowed to dry out between waterings.
Cultivation Methods
Rubus ulmifolius Schott var. inermis (Willd.) Focke, commonly known as the Thornless Elmleaf Blackberry, is a versatile plant that can grow in various soil types and conditions as long as there is proper drainage. The plant prefers partial to full sun, with temperatures between 60 to 85°F. It is best to plant this species in early spring or late fall, spacing them 3 to 4 feet apart.
Watering Needs
Proper watering is essential for the growth and development of Rubus ulmifolius Schott var. inermis. This species requires about 1 inch of water per week, especially during the growing and fruiting season. Watering should be done at the plant's base, avoiding getting water on the leaves to prevent the formation of fungal diseases. It is essential to maintain proper moisture levels in the soil and to avoid overwatering, which could lead to root rot.
Fertilization
Rubus ulmifolius Schott var. inermis requires regular fertilization to enhance its growth and fruit production. A balanced fertilizer with a 10-10-10 NPK ratio is ideal, and it should be applied when new growth appears in the spring. It is essential to follow the recommended dosage to avoid over-fertilization, which can burn the roots and damage the plant. Applying organic fertilizers, such as compost or manure, is also an excellent way to add nutrients to the soil.
Pruning
Pruning is a crucial aspect of caring for Rubus ulmifolius Schott var. inermis as it promotes plant health and increases fruit production. The best time to prune this species is in late winter or early spring before the growing season begins. During pruning, remove all dead, diseased, and damaged canes, leaving only the most vigorous and healthy ones. Also, remove any lateral shoots growing from the base of the plant, as they can compete with the main canes for nutrients and water. It is recommended to wear long sleeves and gloves while pruning to protect yourself from the plant's thorns.
Propagation of Rubus ulmifolius Schott var. inermis (Willd.) Focke
Rubus ulmifolius Schott var. inermis (Willd.) Focke can be propagated via several methods:
Softwood Cuttings
Softwood cuttings can be taken in the late spring or early summer. Select healthy, young shoots that are still tender and green. Cut the shoots to a length of 4-6 inches, making the cut just below a node. Strip the leaves from the bottom two-thirds of the cutting, leaving only a few leaves at the tip. Dip the cuttings in rooting hormone and plant them in a pot filled with a well-draining soil mix. Water well and keep the cuttings in a warm, bright, and humid location until roots have developed.
Division
If the plant has become too large, it can be divided into smaller sections. This is typically done in the early spring or fall when the plant is dormant. Dig around the base of the plant and carefully separate the sections. Make sure each section has a good root system and replant each section in a suitable location. Water well and keep the plants moist until they become established.
Suckers
Rubus ulmifolius Schott var. inermis (Willd.) Focke produces sucker growth from its roots. These suckers can be dug up, separated from the parent plant, and replanted in a suitable location. Make sure each sucker has a good root system. Water well and keep the plants moist until they become established.
Disease Management
One of the most common diseases affecting Rubus ulmifolius Schott var. inermis (Willd.) Focke is anthracnose. This fungal disease can cause leaf spots, stem cankers, and fruit rot. To manage anthracnose, it is recommended to prune affected branches and remove any infected plant debris. Additionally, fungicides can be applied during the growing season to reduce the risk of infection.
Another disease that can affect Rubus ulmifolius Schott var. inermis (Willd.) Focke is powdery mildew. This disease appears as a white, powdery coating on the leaves, shoots, and flowers of the plant. To manage powdery mildew, it is recommended to provide adequate air circulation around the plants and avoid overhead watering. Additionally, fungicides can be applied during the growing season to reduce the risk of infection.
Pest Management
One of the most common pests that affect Rubus ulmifolius Schott var. inermis (Willd.) Focke is the raspberry fruitworm. The larvae of this insect feed on the fruits of the plant, causing damage and reducing fruit yield. To manage raspberry fruitworm, it is recommended to apply insecticides early in the season before the larvae have a chance to feed on the fruit.
Another pest that can affect Rubus ulmifolius Schott var. inermis (Willd.) Focke is the Japanese beetle. These insects feed on the leaves and fruits of the plant, causing damage and reducing fruit yields. To manage Japanese beetles, it is recommended to handpick the insects off of the plants and discard them in soapy water. Additionally, insecticides can be applied to reduce the population of Japanese beetles.
