Origin
Arabis laevigata (Muhl. ex Willd.) Poir. var. missouriensis (Greene) Ahles is a native plant to the United States, specifically in the states of Missouri, Oklahoma, Arkansas, and Texas. It belongs to the family Brassicaceae, which is also known as the mustard family or cabbage family.
Common Names
This plant is commonly known as "Missouri Rockcress" or "Smooth Rockcress". Its scientific name, Arabis laevigata, comes from the Greek word "arabos" which means "very early" in reference to its early blooming period, and "laevigata" which means "smooth" in reference to its leaves.
Uses
Arabis laevigata (Muhl. ex Willd.) Poir. var. missouriensis (Greene) Ahles has many potential uses, especially in traditional medicine. It has been used to treat various ailments such as coughs and colds, headaches, and fever. Some indigenous tribes also used the plant in poultices for treating wounds and skin infections. Additionally, the plant can be used as an ornamental plant in gardens and landscapes due to its beautiful white flowers which bloom in early spring.
General Appearance
This plant is a perennial herb that grows up to 60 cm tall. It has a woody stem at the base, and its leaves are lance-shaped, with smooth edges and a glossy surface. During its blooming period, which occurs in March to May, its flowers grow in clusters at the end of the stems. The flowers are about 1.5 cm in size and are white or pale purple in color. The plant prefers well-drained soils and can grow in full sun to partial shade conditions.
Light Conditions
Arabis laevigata var. missouriensis requires full sun to partial shade for optimal growth conditions. It can tolerate some shade but will not thrive if it does not receive enough sun.
Temperature Requirements
This plant typically grows in USDA hardiness zones 4-8, indicating that it can tolerate a wide range of temperatures. However, it prefers cooler temperatures and can suffer from heat stress in hot climates. The ideal temperature range is between 60-75°F (15-23°C).
Soil Requirements
Arabis laevigata var. missouriensis requires well-draining soil with a pH range of 6.0-7.5. It can tolerate a range of soil types, including loam, clay, and sandy soils. However, the soil must not be too wet, as it can lead to root rot. Adding organic matter to the soil can help improve drainage and fertility.
Cultivation methods
Arabis laevigata var. missouriensis is a hardy perennial plant that thrives in full sun to partial shade. It prefers well-draining soil with a neutral to slightly alkaline pH level. The plant can be propagated by using seeds or cuttings.
If growing from seed, it's essential to sow the seeds in the fall or early winter because the plant requires a period of cold stratification. Alternatively, seeds can be sown in the spring after the danger of frost has passed, but the plant may not flower until the following year.
Cuttings are best taken in the early summer when the plant is actively growing. Cuttings should be taken from healthy plants and should be at least 4 inches long. Dip the cut end of the stem into rooting hormone and plant it in a pot filled with moist potting soil. Keep the soil moist, and the cutting should root within four weeks.
Watering needs
Arabis laevigata var. missouriensis requires moderate watering. It prefers moist soil but can tolerate periods of drought. Overwatering should be avoided as it can lead to root rot and other issues. It's best to water deeply and infrequently, allowing the soil to dry out slightly between each watering session.
Fertilization
The plant doesn't require heavy feeding. A balanced slow-release fertilizer can be applied in the spring to promote healthy growth and blooming. Alternatively, a light feeding with a diluted fertilizer can be applied every four to six weeks during the growing season.
Pruning
Pruning is not necessary for Arabis laevigata var. missouriensis, but it can be helpful in promoting a more compact growth habit and preventing the plant from becoming too leggy. The best time to prune is after the plant has bloomed. Remove any dead or damaged branches and trim back any overgrown areas to maintain the desired shape of the plant.
Propagation of Arabis laevigata var. missouriensis
Arabis laevigata var. missouriensis can be propagated through different methods including seeds and vegetative cuttings.
Seed Propagation
The seeds of Arabis laevigata var. missouriensis can be sowed in the early spring or fall. The recommended depth for the seeds is about 1/8 inch deep in well-drained soil with a temperature range of 60-70°F. The seedlings can emerge in around 7-30 days. Seed propagation of Arabis laevigata var. missouriensis can lead to different characteristics and variations in the offspring.
Vegetative Cuttings
Vegetative cuttings can be taken from the mature plant during the early summer season. The cuttings should be around 4-6 inches long and contain at least two nodes. The bottom nodes should be scraped and treated with rooting hormone before planting in a well-drained soil mix. The cuttings should be kept in a moist, warm environment with moderate light. After few weeks, roots can start developing. Once the plant becomes established, it can be transplanted into the desired location.
Disease Management
Arabis laevigata var. missouriensis is susceptible to various diseases that can cause damage to the plant, such as:
- Anthracnose: This fungal disease causes irregularly shaped black spots and can lead to defoliation. It can be controlled by removing and destroying infected plant parts and applying a copper-based fungicide.
- Downy Mildew: This disease is caused by a fungus, and it appears as yellow spots on the leaves. The infected areas become brown and develop a white coating. The best way to manage downy mildew is by removing infected plant parts and choosing resistant plant varieties.
- Bacterial Blight: This disease occurs due to bacteria and is characterized by brown or black dead areas on the leaves. To control this disease, remove the infected plant parts, avoid overhead watering, and keep the plant dry.
Pest Management
There are some common pests that can attack Arabis laevigata var. missouriensis and cause serious damage to the plant. These include:
- Aphids: These pests are tiny, soft-bodied insects that suck sap from the plant. They can be controlled by washing them off with a strong stream of water or by applying insecticidal soap.
- Spider Mites: These tiny pests are hard to detect and can cause yellowing and wilting of the leaves. They can be controlled by using a forceful spray of water to knock them off the plant or by applying a miticide.
- Slugs and Snails: These pests prefer damp and shady areas and can eat large holes in the leaves. To control slugs and snails, use baits or traps or handpick them off the plant.
Regular monitoring of your plants and identifying any diseases and pests early is critical to successful management. Proper sanitation practices, watering techniques, and overall plant care can also help prevent infestations and infections.
