Origin
Rubus invisus, commonly known as western raspberry, is a species of flowering plant that belongs to the family Rosaceae. The plant is native to the western United States, specifically to the states of Oregon, Washington, and California.
Common Names
Aside from western raspberry, Rubus invisus is also commonly known as Pacific thimbleberry or invisible raspberry due to its small and hard to find fruits.
Uses
The fruits of Rubus invisus are edible, but they are small and difficult to find. They are often used by birds and small mammals as a food source. The plant is also used for medicinal purposes by indigenous people. The Navajo tribe uses the roots to make a tea to cure diarrhea, while the Thompson tribe uses the roots and leaves to make poultices for external wounds and sores.
Appearance
Rubus invisus is a shrubby plant that can grow up to 6 feet tall. It has deciduous leaves, with 3-7 leaflets often coarsely toothed or lobed. The flowers are white or pink, with five petals and numerous stamens. The fruit is a red or blackberry-like aggregate with small drupelets. The plant prefers moist and shady habitats, often found near water sources like streams and wetlands.
Growth Conditions for Rubus invisus (Bailey) Britt.
Rubus invisus (Bailey) Britt. is a shrub species that is commonly found in the eastern regions of North America. The plant prefers a temperate climate with moderate rainfall, moderate temperatures, and full sun exposure for optimal growth. Here are some detailed growth conditions for Rubus invisus:
Light Requirements
Rubus invisus (Bailey) Britt. requires full sun exposure for optimal growth with at least 6 hours of direct sunlight per day. However, it can tolerate partial shade but may not produce as much fruit under such conditions.
Temperature Requirements
The ideal temperature range for the growth of Rubus invisus is between 20 and 30°C (68 and 86°F). The plant can tolerate colder temperatures in the winter, but it may reduce fruit production.
Soil Requirements
The plant prefers well-drained loamy soils with a pH range of 5.5 to 6.5. The soil must retain enough moisture without being waterlogged, as waterlogged soils can lead to root rot. Rubus invisus can also grow in sandy or rocky soils with adequate moisture content, but the soil needs to have good fertility. Regular fertilization can help maintain productivity.
Water Requirements
Generally, Rubus invisus requires moderate watering throughout the growing season. The plant requires adequate moisture for proper growth and fruit development, but overwatering can lead to root rot or excessive vegetative growth. Infrequent deep watering is ideal for the plant.
Other Growing Conditions
Rubus invisus can tolerate mild winds but is not tolerant of strong winds or frost. The plant also requires adequate spacing to avoid overcrowding, which can lead to poor air circulation, increased disease susceptibility, and reduced the productivity of the plant.
Cultivation of Rubus invisus (Bailey) Britt.
Rubus invisus, commonly known as the Dewey’s Bramble, is a deciduous, perennial plant native to North America. It is an easy-to-grow plant that adapts well to a variety of soils and grows best in full sunlight to partial shade. The plant grows best in well-draining and slightly acidic soils, with a pH range of 5.5 to 6.5.
Watering Needs of Rubus invisus (Bailey) Britt.
Regular watering is required for the Rubus invisus plant, especially during the growing season. The plant must be watered at least once a week, and the soil must be kept moist but not waterlogged. Avoid overwatering, as it can lead to root rot, which can be fatal for the plant. During the winter months, reduce the watering frequency and water the plant only when the top inch of the soil dries out.
Fertilization of Rubus invisus (Bailey) Britt.
Regular fertilization is essential for the healthy growth of Rubus invisus. Apply a balanced fertilizer, such as a 10-10-10 or 20-20-20 fertilizer, once every month during the growing season. For best results, apply the fertilizer according to the manufacturer's instructions, and avoid applying it directly to the plant's stems and leaves. Alternatively, you can use organic fertilizers, such as compost or well-rotted manure.
Pruning Rubus invisus (Bailey) Britt.
Pruning is essential for the healthy growth of Rubus invisus. The plant produces fruit on one-year-old canes, so it is essential to prune the plant regularly to encourage new growth and fruit production. Prune the plant in late winter or early spring before the plant starts to grow. Cut all the dead, damaged, and diseased canes to the ground level, leaving only the healthy and vigorous canes. The plant can also be trained to grow on a trellis or a support system for easy maintenance and fruit harvesting.
Propagation of Rubus invisus (Bailey) Britt.
Rubus invisus can be propagated through two main methods: Seeds and Cuttings.
Propagation by Seeds
Seed propagation involves the collection of fruits from healthy plants of Rubus invisus. The fruits need to be ripe and fully developed before they can be harvested. To remove the seeds, you need to crush the fruit and then select only the healthy seeds. Seeds can be sown in trays or pots depending on the quantity available. A well-drained soil mix can be used and you need to press the seeds gently on the soil surface without covering them. The trays or pots should be watered to saturation and then placed in a warm location.
Germination of seeds starts between 1 to 3 months. As the seedlings grow, they need to be transplanted into bigger pots or directly planted outside in the field. Seedlings need to be protected from extreme sunlight and strong winds.
Propagation by Cuttings
Cuttings are the easiest and fastest way of propagating Rubus invisus. Cuttings can be taken from the current season's stem growth, select healthy and strong stems with no signs of disease or pest damage.
Prepare the cuttings by removing the bottom leaves to leave a stem of about six inches. Dip the cut end in rooting hormone powder to boost its rooting. Stick the prepared cuttings in a well-drained soil mix that is moistened to near saturation. Cuttings can be stuck directly in the field or in pots depending on the environment they will be grown in. Cuttings need to be watered regularly to keep the soil moist.
After two to three weeks, the cuttings should have started rooting. You can check by gently tugging on the stem to see if there is any resistance. Once the cuttings have developed a good root system, they can be transplanted to their permanent location.
Disease Management
Rubus invisus is susceptible to several diseases that can affect its growth and productivity. The common diseases that affect Rubus invisus include:
- Crown rot: This disease can be caused by several fungi and can cause wilting and death of the plant. Crown rot can be managed by avoiding low-lying areas with poor drainage and practicing crop rotation.
- Anthracnose: This disease can be caused by different fungi species and can result in spotting and lesions of the leaves. The disease can be managed by pruning diseased branches, avoiding overhead watering, and applying fungicides.
- Botrytis gray mold: This fungal disease can cause wilting and decay of the flowers and fruits. To manage the disease, infected plant parts should be removed, and fungicides applied.
Pest Management
Rubus invisus can also be infested by several pests that can cause significant damage to the plant. The common pests that infest Rubus invisus include:
- Spider mites: Spider mites feed on the sap of leaves, causing the plant to weaken and defoliate. To control spider mites, apply insecticides and maintain high humidity in the area.
- Japanese beetles: The adult Japanese beetles feed on the leaves, flowers, and fruits, causing significant damage to the plant. To control Japanese beetles, handpick them or use insecticides. Planting trap crops such as roses or grapes may also be effective.
- Blackberry psyllid: The blackberry psyllid feeds on the new tissue, causing leaf curling and stunting of the plant. To manage the pest, prune the affected plant parts and apply insecticides.
