Overview:
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. is a small herbaceous flowering plant that belongs to the Brassicaceae family. It is a subspecies of Draba nivalis Lilj., commonly known as Alpine Draba.
Origin:
The plant is native to the high mountains of western North America, including the Rocky Mountains and the Sierra Nevada. It can be found growing at elevations of up to 4,500 meters above sea level.
Common Names:
The plant is commonly known as Thompson's Draba, named after the American botanist and collector, John W. Thompson.
General Appearance:
The plant is a low-growing perennial that reaches a height of 2-8 cm. It has small, grayish-green leaves that are about 1-3 cm long. The flowers are white or yellow and grow in small clusters on the tips of the stems. The plant blooms from June to August.
Uses:
Thompson's Draba is primarily used for ornamental purposes due to its attractive appearance. It is commonly found in rock gardens and alpine meadows. It is also used as a food source by some wildlife species, including bighorn sheep and mountain goats.
Light Requirements
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. thrives in full sunlight or partial shade. However, it needs direct sunlight for at least six hours every day to grow and bloom properly. Lack of sunlight can result in stunted growth and poor flowering.
Temperature Requirements
The plant prefers cool to cold temperatures. It can tolerate warm temperatures but grows best in cool conditions. The ideal temperature for its growth is between 10-15°C (50-59°F). The plant can survive in temperatures as low as -20°C (-4°F) and as high as 25°C (77°F), but it may affect its growth rate.
Soil Requirements
The plant prefers well-drained and moist soil. It grows best in rocky or gravelly soil, rich in organic matter. The optimal soil pH range for its growth is between 6.0 to 7.5. However, it can tolerate slightly acidic to slightly alkaline soil conditions.
It can grow in various soil types, including loam, sand, and clay, provided it is well-draining. It is also adapted to grow in soil with low nutrient levels due to its ability to fix nitrogen from the atmosphere using specialized root nodules.
Cultivation Methods
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. is a perennial plant that prefers to grow in a sunny location with well-draining soil. It is cold hardy and can be grown in USDA hardiness zones 3 to 9. It is best to plant this plant in the spring or fall, giving it enough time to establish roots before the hot summer months or winter frost.
When planting, space the plants about 6 inches apart and ensure that the soil is prepared with good drainage. The roots of this plant are shallow, so ensure that it is surface planted and not too deeply buried. After planting, water the plant well to help the roots settle into the soil.
Watering Needs
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. prefers to grow in moist soil but can tolerate brief periods of drought. It is important not to overwater the plant as it can suffer from root rot. Ensure that the soil is well-draining to prevent waterlogging, which can also lead to root rot.
The plant's watering needs can vary depending on the weather and soil conditions. When in doubt, stick your finger into the soil about an inch deep to see if it feels dry – if so, water the plant. Watering in the early morning or late evening and avoiding the hottest parts of the day can also help the plant retain moisture.
Fertilization
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. is a low-maintenance plant and does not require heavy fertilization. However, you can fertilize the plant with a balanced fertilizer during the growing season to encourage healthy growth.
Apply fertilizer according to the instructions on the package, being careful not to over-fertilize the plant. Over-fertilization can lead to a build-up of salts in the soil and cause plant burn or damage.
Pruning
Pruning is not necessary for Draba nivalis Lilj. var. thompsonii C.L. Hitchc. However, removing damaged or dead leaves and stems can improve the plant's appearance. These parts of the plant can also attract pests and disease.
If the plant becomes overgrown or crowded, you can divide it in the spring or fall to create new plants. Dig up the plant's root system and separate it into smaller pieces, ensuring that each section has enough leaves and healthy roots. Replant the divisions in a new location or container with fresh soil and water well.
Propagation of Draba nivalis Lilj. var. thompsonii C.L. Hitchc.
Draba nivalis Lilj. var. thompsonii C.L. Hitchc., commonly known as Thompson's draba, is a low-growing alpine plant that is native to western North America. Propagation is an essential aspect of maintaining healthy populations of this plant in gardens and conservation areas.
Propagation Methods
The propagation of Thompson's draba can be achieved through the following methods:
Seed Propagation
Thompson's draba produces tiny seeds that can be collected from the plants in late summer when they are fully mature. The seeds can be directly sown in a well-draining, sterile seed-starting mix. The pots must be kept moist, and the plants must receive adequate light and warmth until the seedlings emerge.
Cutting Propagation
Cutting propagation is another method of propagating Thompson's draba. The plant can be propagated by taking cuttings from the stems and rooting them in a well-draining, moist medium. The cuttings should be taken during the plant's dormant seasons, i.e., early spring or late fall. The cuttings should be dipped in rooting hormone before planting to increase their chances of rooting.
Overall, both seed propagation and cutting propagation are effective methods of propagating Thompson's draba. The plants are easy to propagate, making them ideal for gardeners looking to increase their stock or for conservationists looking to establish new populations of the species.
Disease management
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. is susceptible to various diseases that can affect its growth, development, and overall health. The following are common diseases that might affect this plant:
- Leaf Spot: This fungal infection appears as small, dark spots on the plant's leaves. To manage this disease, remove all the affected leaves and avoid overhead watering, which can spread the infection.
- Clubroot: This disease is caused by a soil-borne pathogen that attacks the plant's roots, leading to stunted growth and wilted leaves. To manage this disease, avoid planting this species in areas where previous clubroot infections have occurred.
- Downy Mildew: This disease appears as fuzzy, white patches on the undersides of the leaves. To manage this disease, use a fungicide on the infected plants and improve air circulation by removing weeds and dead plant material from the area.
Pest management
Draba nivalis Lilj. var. thompsonii C.L. Hitchc. is commonly attacked by various pests that can affect its growth, development, and overall health. The following are some of the common pests that might affect this plant:
- Aphids: Aphids are tiny, pear-shaped insects that suck the plant's sap, leading to stunted growth and yellowed leaves. To manage this pest, use insecticidal soap or neem oil to kill the infestation.
- Cabbage Worms: Cabbage worms are green-colored caterpillars that feed on the plant's leaves, resulting in extensive damage to the foliage. To manage this pest, use BT (Bacillus thuringiensis) or hand-pick the caterpillars and drop them into a bucket of soapy water.
- Slugs: Slugs are slimy, brown-colored pests that feed on the plant's foliage, causing irregular holes in the leaves. To manage this pest, use a slug bait or create a barrier around the plant using copper tape or diatomaceous earth.
