Overview of Draba howellii S. Wats.
Draba howellii S. Wats. is a perennial herb endemic to Oregon in the US and belongs to the family Brassicaceae. The plant was named after Thomas Howell, a noted botanist who discovered it in the Cascade Range in Oregon.
Common Names
The plant is commonly known as Howell's Draba, Howell's alpine draba, or Howell's whitlow-grass.
Uses
Although there are no known medicinal uses for this plant, it is often cultivated as an ornamental plant in rock gardens and alpine meadows. It is also used in ecological restoration projects because it helps in the rehabilitation of degraded and disturbed areas.
Appearance
Draba howellii S. Wats. is a small plant that grows to a height of about 3-6 cm. The leaves are narrow and oblong, measuring about 1-3 cm in length and are hairy in texture. The flowers of Howell's Draba are bright yellow and bloom from April to late June. Each flower has four petals measuring about 3-4 mm long. The fruit is a cylindrical, hairy capsule that measures about 4-6.5 mm long.
Light Requirements
Draba howellii S. Wats. requires full sun to grow properly. It is a sun-loving plant that needs at least 6 hours of direct sunlight every day. Lack of proper sunlight may lead to poor growth, reduced flower production, and leggy stems.
Soil Requirements
The plant prefers moist, well-draining soil that is slightly acidic to neutral (pH 6.0-7.0) and rich in organic matter. The soil should also be loose and friable to allow for adequate root development. Any heavy or compacted soils should be amended with sand, perlite, or other organic matter to improve the soil structure.
Temperature Requirements
Draba howellii S. Wats. is adapted to cold climates and can grow in temperatures ranging from 0-25 °C (32-77 °F). However, it prefers cooler temperatures with a range of 10-20 °C (50-68 °F) to grow optimally. Extreme heat or cold may cause stress to the plant, affecting its growth and development.
Cultivation Methods
Draba howellii S. Wats. is a low-growing and spreading evergreen perennial that grows best in USDA hardiness zones 4 to 8. It prefers full sun to partial shaded areas and is commonly grown in rock gardens, alpine gardens, and as a ground cover. The plant thrives in well-drained soil with a neutral to slightly alkaline pH level.
Watering Needs
Draba howellii S. Wats. requires regular watering, especially during the growing season, to keep the soil consistently moist. Avoid overwatering, which can result in root rot and other diseases. During the winter dormant period, reduce watering to allow the soil to dry out partially before watering again.
Fertilization
Draba howellii S. Wats. is a low-maintenance plant that does not require regular fertilization. However, feeding the plant with a balanced fertilizer once in early spring and again in late summer can benefit its growth and health. Use a slow-release fertilizer and follow the manufacturer's instructions.
Pruning
Draba howellii S. Wats. does not require extensive pruning. However, deadheading the spent blooms promotes new growth and prolongs the flowering period. Use pruning shears to trim back any dead, damaged, or diseased stems and branches to maintain its shape and promote healthy growth. Do this in late winter or early spring when the plant is still dormant.
Propagation of Draba howellii S. Wats.
Propagation of Draba howellii S. Wats. can be accomplished through different methods.
Seed Propagation
Seeds are the best way to propagate Draba howellii S. Wats. and are readily available from nurseries, plant stores, or online. They are usually sown in a cold frame during the fall, where they will require stratification. Stratification is a process that mimics the winter conditions essential to break seed dormancy. It involves keeping the seeds in moist sand, peat moss, or vermiculite at temperatures between 34 and 41 °F for two to four weeks. After this period, the seeds will be ready for sowing. They can be planted in a suitable potting mix with a pH range of 5.5 to 7.0. It is recommended to cover the seeds with a thin layer of soil, water them, and place them in a warm location with bright, indirect light. Germination occurs after around 20 to 30 days, and once the seedlings have multiple leaves, they can be moved to individual containers or directly to the garden once they establish roots.
Division
Division is a propagation method used to obtain multiple plants from a mature Draba howellii S. Wats. plant. It implies separating the roots and foliage to create sections that can grow on their own. This method requires patience and care as the plant has a delicate root system. It is best to perform this activity in early spring before new growth emerges. Dig up the plant carefully, shake off excess soil, and identify the natural division points. Cut the plant into sections with a sharp, clean knife or shears. Each section should have a portion of the leaves and roots. The sections should be replanted in the appropriate location and watered thoroughly.
Conclusion
Both seed propagation and division are effective ways to propagate Draba howellii S. Wats. If the proper steps are taken, the plants should grow strong and healthy.
Disease and Pest Management for Draba howellii S. Wats.
Draba howellii S. Wats., commonly known as Howell's draba, is an annual herbaceous plant that is native to western North America. It is a hardy plant that requires minimal care, but like all plants, it can be susceptible to certain diseases and pests that can impact its growth and health.
Common Diseases of Draba howellii S. Wats.
One of the most common diseases that can affect Draba howellii S. Wats. is powdery mildew. Powdery mildew is a fungal disease that appears as a white or gray powdery coating on leaves, stems, and flowers. To manage powdery mildew, it is important to ensure good air circulation around the plant, prune infected branches, and avoid getting water on the foliage. Fungicides can also be used to control the disease.
Another disease that can affect Draba howellii S. Wats. is damping off. Damping off is a fungal disease that affects seedlings and young plants, causing them to wilt and die. To prevent damping off, it is important to maintain proper soil moisture levels, use sterile potting soil, and avoid overcrowding seedlings in containers.
Common Pests of Draba howellii S. Wats.
One of the most common pests that can affect Draba howellii S. Wats. is aphids. Aphids are small, soft-bodied insects that suck sap from the plant, causing stunted growth and distorted leaves. To manage aphids, they can be physically removed or sprayed with insecticidal soap or neem oil.
Another pest that can affect Draba howellii S. Wats. is flea beetles. Flea beetles are small, shiny black beetles that leave small holes in the foliage of the plant. To manage flea beetles, it is important to remove any crop debris where the beetles might overwinter and to use insecticidal dust or spray.
In conclusion, Draba howellii S. Wats. is a relatively hardy plant but may be susceptible to certain diseases and pests. Careful management and vigilant monitoring can help prevent and address any issues that may arise.
