Origin
The Arabis laevigata (Muhl. ex Willd.) Poir. var. burkii Porter, commonly known as Burk's Rock Cress, is native to eastern and south-central United States. It primarily grows in rocky and sandy soils in open woods, glades, and along riverbanks.
Common Names
Burk's Rock Cress is also known by other common names such as Smooth Rock Cress, Smooth Yellow Rock Cress, and Burk's Yellow Rock Cress.
Uses
Arabis laevigata var. burkii is commonly used for ornamental purposes in rock gardens and borders because of its attractive yellow flowers that bloom in spring. It is also used for erosion control and soil stabilization along slopes and roadsides.
General Appearance
Burk's Rock Cress is a herbaceous, perennial plant that grows up to 20 inches in height. It has an upright and branching stem with wavy-edged, lanceolate leaves that are about 2 inches long. The plant produces clusters of bright yellow flowers at the top of the stem, each with four petals. The flowers are about half an inch in diameter and bloom in April or May. The fruit is a linear seed pod that splits open when ripe, releasing small, round seeds.
Light Requirements
Arabis laevigata var. burkii requires full sunlight to grow well. Inadequate sunlight can cause the plant to become leggy and produce fewer flowers. Therefore, it is best to plant the species in a location where it can receive full sunlight for most of the day.
Temperature Requirements
Arabis laevigata var. burkii is a hardy plant that can grow in a wide range of temperatures. However, optimal growth occurs in the temperature range of 60-75°F. In hot, dry conditions, the plant may require regular watering to prevent it from becoming stressed.
Soil Requirements
The plant prefers well-drained, sandy soils with a neutral to slightly alkaline pH. It can tolerate slightly acidic soils, but too much acidity can be detrimental to the growth of the plant. The soil should also be rich in organic matter and nutrients, which can be achieved through the addition of compost or other organic amendments.
Cultivation Methods
Arabis laevigata (Muhl. ex Willd.) Poir. var. burkii Porter requires a well-drained soil and a spot that receives full sunlight. It can also tolerate partial shade. The plant can be propagated by seeds or cuttings. While planting, make sure to space them at least 12 inches apart, especially if you are planting more than one.
Watering Needs
Arabis laevigata (Muhl. ex Willd.) Poir. var. burkii Porter should be watered regularly and deeply. It needs regular watering in the first few weeks to establish roots. However, once established, it can tolerate drought. During hot and dry spells, it is important to increase the frequency of watering.
Fertilization
Arabis laevigata (Muhl. ex Willd.) Poir. var. burkii Porter does not require a lot of fertilization. However, you can apply a balanced fertilizer in the spring. Make sure to follow the instructions on the label carefully.
Pruning
Arabis laevigata (Muhl. ex Willd.) Poir. var. burkii Porter does not require pruning. However, it is a good practice to remove dead or damaged leaves and cut back the stems after the first bloom to promote more growth and blooming next season. Pinching back the tips of the plant can also encourage bushier growth.
Propagation of Arabis laevigata var. burkii
Arabis laevigata var. burkii can be easily propagated through vegetative and sexual methods.
Vegetative Propagation
One of the easiest ways to propagate Arabis laevigata var. burkii is through cuttings. Take a cutting of a healthy stem, and remove the leaves from the bottom inch of the stem. Dip the cut end of the stem in rooting hormone, and plant it in a pot filled with fresh potting soil. Water the pot thoroughly, and place it in a warm, bright area. The cutting should begin to root in a few weeks. Once roots have formed, transplant the new plant into a larger container or into the ground.
Sexual Propagation
Arabis laevigata var. burkii can also be propagated sexually through seed. Collect ripe seed capsules in the fall, and store them in a cool, dry location. In the spring, sow the seeds directly into the ground, or into pots filled with fresh potting soil. Lightly cover the seeds with soil, and keep the soil moist until the seeds have sprouted. Once the seedlings have developed their first true leaves, transplant them into larger containers or into the ground.
Disease Management
The most common disease that affects Arabis laevigata var. burkii is powdery mildew. Powdery mildew appears as a white, powdery substance on the leaves, stem, and other parts of the plant. This disease can weaken the plant and make it more susceptible to other diseases or pests. To manage powdery mildew, it is best to prune away any infected areas of the plant and dispose of them properly. Additionally, make sure the plant is properly spaced to allow for good air circulation around the plant. Fungicides can also be used to manage powdery mildew.
Another common disease that affects Arabis laevigata var. burkii is leaf spot. Leaf spot appears as small, brown spots on the leaves that can eventually cause the leaves to die and fall off. To manage leaf spot, it is best to prune away any infected areas of the plant and dispose of them properly. Additionally, make sure the plant is properly spaced to allow for good air circulation around the plant. Fungicides can also be used to manage leaf spot.
Pest Management
The most common pest that affects Arabis laevigata var. burkii is the flea beetle. Flea beetles are small, black beetles that can quickly damage the leaves of the plant. To manage flea beetles, it is best to use row covers to protect the plant from the beetles. Additionally, you can spray the plant with insecticidal soap or neem oil to manage the flea beetles.
Another pest that can affect Arabis laevigata var. burkii is the cabbage worm. Cabbage worms are green caterpillars that can quickly damage the leaves of the plant. To manage cabbage worms, it is best to use row covers to protect the plant from the worms. Additionally, you can handpick the worms off the plant or use a biological control, such as Bacillus thuringiensis, to manage the cabbage worms.
