Origin
Arabis pulchra var. duchesnensis Rollins, commonly known as Duke's rockcress, is a plant species native to the western United States, specifically found in the states of Idaho, Montana, Nevada, Oregon, and Utah. It typically grows in rocky areas and dry slopes from 500-2500 meters in elevation.
Common Names
The plant is commonly known as Duke's rockcress or Duchesne rockcress. The name "Duke's rockcress" comes from its discovery by Benjamin M. Duggar while he was in the service of Duke University. The name "Duchesne rockcress" is named after Antoine Nicolas Duchesne, a prominent French botanist.
Uses
Arabis pulchra var. duchesnensis Rollins has no known culinary or medicinal uses. It is primarily used as an ornamental plant in rock gardens and sunny borders due to its delicate white flowers and its tolerance for dry, rocky soils. It is also occasionally used in habitat restoration projects for its erosion control properties.
General Appearance
Duke's rockcress is a perennial herb that typically grows up to 10-20 cm in height with a spread of 30 cm. It has hairy stems that often branch out. The leaves are oval-shaped with serrated edges, and they typically grow to be 2-6 cm long. The flowers of the plant are small, white, and have four petals. They grow in clusters, and the flowering period occurs from May to August. The seedpods are long, narrow, and curved. They contain many small seeds that are dispersed by wind.
Light Requirements
The Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins typically requires full sun to partial shade for proper growth. However, during hot summer months, the plant may benefit from partial shade to prevent excessive heat and drought stress.
Temperature Requirements
The plant can grow in a wide range of temperature conditions, but it prefers cooler temperatures between 60°F and 75°F. Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins can tolerate frost and snow, but prolonged exposure to extreme hot or cold temperatures may cause damage to the plant.
Soil Requirements
The plant prefers well-draining soil that is moist but not soggy. Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins can tolerate a wide range of soil types, including clay, loam, and sandy soils. It is recommended to maintain a slightly acidic to neutral soil pH range of 5.5 to 7.0. It is also suggested to amend the soil with organic matter such as compost to improve the soil's fertility.
Cultivation Methods
The Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins is a plant variety that requires a well-draining soil that is rich in organic matter. It also requires a consistent supply of moisture and plenty of sunlight. It grows well in USDA hardiness zones 4-9, which means it can withstand temperatures as low as -20°F (-29°C) to 20°F (-6°C).
It is best to plant the Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins in the spring or fall. The plant should be spaced at least 6-8 inches apart and planted at a depth of around 1 inch. It is also important to ensure that the plant is protected from strong winds, which can damage the delicate foliage.
Watering Needs
The Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins requires consistent watering to thrive. It is important to ensure that the soil is moist but not waterlogged. Overwatering can lead to root rot, which can be fatal to the plant. Young plants should be watered more frequently than established plants. You should also avoid watering the plant from above because it can damage the foliage and encourage the development of fungal diseases.
Fertilization
The Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins requires regular fertilization with a complete fertilizer. You should fertilize young plants in the spring, and established plants should be fertilized in the spring and fall. Be careful not to over-fertilize the plant, which can lead to too much foliage growth at the expense of flowers.
Pruning
The Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins does not require much pruning. However, if you want to promote bushier growth, you can pinch back the stems in the spring before the plant starts to bloom. Deadheading spent flowers can also encourage the production of new blooms. It is also important to remove any diseased or damaged foliage to prevent the spread of disease.
Propagation of Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins
The Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins can be propagated through various methods including:
Seed Propagation
The easiest way to propagate Arabis pulchra is by seed. Seeds of this plant can be sown in early spring in well-drained soil. Before sowing, the soil should be moistened. The seeds should then be sown on the surface of the soil and covered lightly with soil. It is important to keep the soil moist until the seedlings have sprouted. It takes approximately 2-3 weeks for the seedlings to emerge. When they reach a height of around 5-7 cm, they can be transplanted to their permanent location.
Cuttings
Another way to propagate Arabis pulchra is through taking cuttings. Softwood cuttings can be taken in late spring or early summer, when the plant is actively growing. A 5-10cm long cutting can be taken from a healthy plant and dipped in rooting hormone. The cutting should be planted in a well-draining soil mixture and placed in a shaded location. The soil should be kept moist, and the cutting should take root within four to six weeks. Once the cuttings have established roots, they can be transplanted to their permanent location.
Division
Arabis pulchra can also be propagated through division. This is usually done in the fall. The plant should be dug up and carefully separated into small sections. Each section should have healthy roots and at least one new shoot. The divided plants can then be planted in their permanent location. It is important to water these plants frequently until they become established.
Disease Management
Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins is relatively disease-resistant, but it can still fall victim to several fungal and bacterial diseases. Here are some common diseases that affect this plant and ways to manage them:
Black Spot
Black spot is a fungal disease that displays circular, black lesions on the leaves of the plant. The disease can be managed by removing affected leaves and pruning the plant to increase airflow. Fungicide treatments can also be applied to the plant, especially during seasons that promote the rapid spread of the disease.
Downy Mildew
Downy mildew thrives in humid, moist areas of the plant. The leaves of the plant display yellow blotches on the upper surface of the leaf with whitish, cottony growths on the underside. Downy mildew can be managed by removing affected leaves and improving the airflow in the plant's environment.
Pest Management
Arabis pulchra M.E. Jones ex S. Wats. var. duchesnensis Rollins can be comparatively vulnerable to several types of pests. Here are some common pests and ways to manage them:
Aphids
Aphids are tiny insects that can infect the plant by sucking the sap from its leaves. They usually appear in colonies on the underside of leaves and secreting honeydew. To manage aphids, use an insecticidal soap or spray to treat the plant. Predators like ladybugs can also be relied on to eradicate aphids.
Slugs
Slugs usually appear in damp environments and often cause damage to the leaves of the plant. They can be managed by reducing the humidity around the plant, placing copper tape around the base of the plant, or setting up bait and traps around the plant.
Whiteflies
Whiteflies, as the name implies, appear as tiny, white flies, usually on the underside of plant leaves. They can cause damage by consuming the plant's sap, slowing its growth, and degrading its health. To manage whiteflies, employ natural predators like ladybugs and lacewings or use insecticides to kill the flies.
