Overview
Rubus coronarius (Sims) Sweet is a deciduous shrub that belongs to the rose family, Rosaceae. It is widely cultivated for its pleasant fragrance, ornamental and medicinal values.
Origin and Distribution
The plant is native to Europe, from Spain and Portugal to eastern Europe and western Asia, and has been introduced in many parts of the world as an ornamental plant. It grows best in well-drained soils with full sun to partial shade.
Common Names
The plant is commonly known as Garland flower, Flowering raspberry, or European raspberry. Additionally, 'Akebia quinata' is often referred to as "the chocolate vine", a name shared by Rubus coronarius due to the chocolate scent of its flowers.
Appearance
Rubus coronarius is a deciduous shrub that grows up to a height of 1-2 meters. It bears slender, arching branches that are covered with soft spines. The leaves are pinnately divided and have 5-7 leaflets which are green and toothed along the margins. The flowers are pink to white, and have a strong pleasant fragrance that smells like chocolate. The fruits are red, spherical to ovate druplets that are edible but not typically eaten.
Uses
The flowers of Rubus coronarius are used in perfumes and toiletries due to their fragrance. The dried leaves of the plant are used in herbal teas and infusions as they are considered to possess medicinal values. The plant is also used ornamentally, especially in cottage gardens.
Light Requirements
Rubus coronarius, commonly known as the fragrant flowering raspberry, requires full or partial sunlight for optimal growth. Full sun exposure enhances flowering and fruiting while partial shade helps in reducing plant stress during hot weather.
Temperature Requirements
Rubus coronarius plants prefer temperatures that range from 60°F to 75°F. They can tolerate light frost, but in areas with extreme winters, the plants require proper winter protection. The ideal temperature range for their growth is between 70°F to 75°F during the day and 60°F to 65°F at night.
Soil Conditions
These plants require well-drained soil with a pH range of 5.5 to 7.0. The soil should be rich in organic matter, and the addition of compost improves drainage while enhancing soil fertility. Rubus coronarius thrives in sandy loam or loamy soils with good aeration and water retention capabilities.
Cultivation
Rubus coronarius, commonly known as the fragrant flowering raspberry, is a hardy shrub that is relatively easy to grow. It is best planted in full sun and well-draining soil that is kept moist. The plant is hardy in USDA zones 5-8. It is advised to plant the shrub in early spring or late summer, and spacing of 4-5 feet should be between each plant.
Watering
Watering is crucial to the growth of Rubus coronarius. Water the plant regularly, especially during the hot months and dry weather, to keep the soil moist but not waterlogged. It is recommended to use a soaker hose or drip irrigation system, which reduces water waste and ensures that the plant gets the right amount of water it needs. However, overwatering should be avoided as it can lead to root rot.
Fertilization
Although Rubus coronarius doesn't require much fertilization, adding compost to the soil before planting can provide the necessary nutrients for the plant's growth. Use a balanced fertilizer, with equal amounts of nitrogen, phosphorus, and potassium, once a year during the plant's active-growth season, which is usually in early spring or late summer.
Pruning
Pruning is essential to maintain the shape, size, and health of Rubus coronarius. Prune the plant in late winter or early spring before the plant begins to bloom. Remove the dead or damaged canes, as well as the older canes, leaving only the younger, healthier canes. Thin out the canes as needed, but do not remove more than 25 percent of the plant's canes in one year. Pruning will encourage new growth and flowering.
Propagation of Rubus coronarius (Sims) Sweet
Rubus coronarius (Sims) Sweet, commonly known as Roseate, is a deciduous shrub that is native to southern Europe and western Asia. The plant is commonly propagated through cuttings or layering methods.
Cuttings
Softwood cuttings are taken in late spring or early summer. The cutting should have four to five nodes and should be 6-8 inches long. Remove all the leaves from the bottom third of the cutting and dip the bottom of the stem in rooting hormone. Insert the stem into a well-drained rooting medium, and keep it moist until it roots.
Semi-hardwood cuttings can be taken in late summer or early fall. The cutting should be 6-8 inches long with two or three nodes. Remove all the leaves from the bottom half of the cutting and dip the bottom of the stem in rooting hormone. Insert the stem into a well-drained rooting medium, and keep it moist until it roots.
Layering
Air layering can be done in early spring or early fall. Select a healthy, flexible stem that is low to the ground, and strip the bark off a 6-8 inch section of the stem. Apply rooting hormone to the exposed wood and wrap the area with moist sphagnum moss. Cover the moss with plastic wrap and secure it with a rubber band. Keep the moss moist, and roots will form in a few weeks. Once the roots reach 1-2 inches long, cut the rooted section from the parent plant and plant it in a well-drained soil mixture.
Tip layering can be done in early spring or early fall. Select a healthy, flexible stem that is low to the ground, and make a shallow trench beside the stem. Lay the stem in the trench, cover it halfway with soil, and pin it in place with a U-shaped pin. Keep the soil moist, and roots will form in a few weeks. Once the roots reach 1-2 inches long, cut the rooted section from the parent plant and plant it in a well-drained soil mixture.
Disease Management:
Rubus coronarius (Sims) Sweet, commonly known as fragrant raspberry or flowering raspberry, can be affected by various diseases that can hinder its growth and productivity. Here are some common diseases and ways to manage them:
Anthracnose:
Anthracnose is a fungal disease that affects the leaves, shoots, and fruit of Rubus coronarius. Symptoms include round, sunken lesions on leaves and stems that eventually turn brown and crispy. To manage anthracnose, it's important to ensure good air circulation and proper sanitation. Remove any infected plant debris, and avoid overhead watering. Fungicides can also be used to control anthracnose, but it's essential to follow the manufacturer's instructions.
Septoria Leaf Spot:
Septoria leaf spot is a fungal disease that primarily affects the leaves of Rubus coronarius. The signs of septoria leaf spot include small, brownish-black spots with grayish-white centers, which can coalesce to form larger lesions. The leaves may turn yellow and drop prematurely. You can manage septoria leaf spot by removing infected leaves and improving air circulation around the plant. Fungicides can also be used to control this disease.
Verticillium Wilt:
Verticillium wilt is a soil-borne fungal disease that can affect many different plants, including Rubus coronarius. The symptoms include yellowing leaves, wilting, and dieback that starts at the tips of the branches. Unfortunately, there's no cure for verticillium wilt, so prevention is crucial. Avoid overcrowding the plant, and keep it stress-free by providing adequate water and nutrients. Additionally, avoid planting Rubus coronarius in soil that has a history of verticillium wilt.
Pest Management:
Aside from diseases, pests can also be a problem for Rubus coronarius. Here are some common pests and ways to manage them:
Japanese Beetle:
Japanese beetles are a common pest that can cause significant damage to the foliage of Rubus coronarius. The beetles feed on the leaves, leaving behind skeletonized leaves with only the veins remaining. You can manage Japanese beetles by manually removing them from the plant, placing pheromone traps to attract and trap them, or using insecticides. It's essential to follow the manufacturer's instructions when using insecticides.
Spider Mites:
Spider mites are tiny pests that can create a network of webbing on the underside of the leaves of Rubus coronarius. They suck the sap from the leaves, leading to discoloration and eventually, leaf drop. You can manage spider mites by spraying the plant with a strong stream of water to dislodge them from the leaves. Additionally, you can use insecticidal soap or neem oil to control spider mites.
Cane Borers:
Cane borers are insects that lay their eggs on the canes of Rubus coronarius. The larvae then bore into the canes, causing them to wilt and die. To manage cane borers, remove and destroy any wilting or damaged canes. Additionally, apply insecticides to the remaining canes to prevent further infestation.
