Overview of Arabis arcuata (Nutt.) Gray var. rubicundula Jepson
Arabis arcuata (Nutt.) Gray var. rubicundula Jepson, commonly known as the Coast Rockcress or Red Rock Cress, is a rare perennial plant species in the mustard family (Brassicaceae).Origin and Distribution
The Coast Rockcress is native to the western coast of North America, ranging from British Columbia to central California. It mainly grows in coastal and montane regions, in rocky or sandy soils, and is commonly found in open habitats such as ridges, bluffs, and cliffs.General Appearance
The Coast Rockcress is a low-growing herbaceous perennial that reaches up to 30 cm tall. It has simple, hairy, toothed leaves that are up to 6 cm long, and form a rosette at the base of the stem. The stem is erect and branching, and bears small pink to reddish-purple flowers in clusters at the ends of the branches. The flowers have four petals and six stamens, and bloom from March to May.Uses and Conservation Status
The Coast Rockcress is primarily used as an ornamental plant in rock gardens or as a ground cover. It has no known medicinal or culinary uses but does bring aesthetic value. Due to its restricted distribution and habitat loss, the Coast Rockcress is a threatened and protected species in many regions. It is currently listed as a species of concern in California and Oregon. Efforts are ongoing to conserve and restore this rare plant species and its habitats.Light Requirements
Arabis arcuata (Nutt.) Gray var. rubicundula Jepson is a sun-loving plant that thrives well in full sun to partial shade conditions. It requires at least six hours of direct sunlight to grow properly. If the plant is planted in dense shade, it may not grow as tall as it usually does.
Temperature Requirements
The plant can grow in various climatic conditions. However, it prefers a moderate climate with temperatures ranging from 60-75 degrees Fahrenheit. If the temperature drops below freezing, it may wither away, and frost may destroy it. In hot temperatures, the plant may require extra watering to stay hydrated.
Soil Requirements
The Arabis arcuata (Nutt.) Gray var. rubicundula Jepson requires well-drained soils that retain moisture but do not become waterlogged. The plant grows best in slightly acidic soils with a pH level of 6.0 to 7.5. Soil with too high or low pH levels may result in stunted growth or death of the plant. Additionally, regular fertilization using a slow-release fertilizer helps promote healthy growth and abundant flowers.
Cultivation
Arabis arcuata (Nutt.) Gray var. rubicundula Jepson is a hardy perennial plant that thrives in zones 5-8. It prefers full sun exposure and well-drained soil with a pH of 6.5-7.5. It can be propagated by seeds or root division.
Watering Needs
The watering needs of Arabis arcuata (Nutt.) Gray var. rubicundula Jepson vary according to the season. During the growing season, it requires moderate watering, ensuring that the soil remains moist but not waterlogged. In winter, it requires less water, as the plant goes dormant. It is essential to avoid overwatering, which can lead to root rot.
Fertilization
Arabis arcuata (Nutt.) Gray var. rubicundula Jepson does not require heavy fertilization. A balanced fertilizer can be applied once in early spring, before the plant blooms. It is crucial to avoid overfertilization, which can lead to rapid, weak growth.
Pruning
Pruning is essential to maintain the shape and the health of Arabis arcuata (Nutt.) Gray var. rubicundula Jepson. After blooming, trim back the spent flower stalks. This process encourages the plant to produce more blooms. In late fall, when the plant becomes dormant, cut back the stems to the ground level. This step protects the plant from winter damage, and it rejuvenates the plant in the spring.
Propagation of Arabis arcuata var. rubicundula
Arabis arcuata var. rubicundula can be propagated through seed and vegetative methods.
Seed propagation
The seeds of Arabis arcuata var. rubicundula can be collected from mature fruits. The best time to collect the seeds is when the fruits turn brown and start to split open. The collected seeds can be stored in a cool and dry place until ready for planting.
To successfully grow Arabis arcuata var. rubicundula from seed, it is essential to provide the seeds with the right conditions for germination. This species requires a period of cold stratification to break dormancy. The seeds should be planted in a moist and well-draining soil mixture in a container and kept in a refrigerator at a temperature of 4°C for three to four weeks. After the stratification period, the seeds can be moved to a bright, warm place to germinate. Seedlings should emerge within two to three weeks.
Vegetative propagation
Arabis arcuata var. rubicundula can also be propagated through vegetative methods such as stem cuttings and division.
Stem cuttings should be taken from healthy plants in the spring or early summer. The cuttings should be four to six inches long and should not have flowers or buds. The cuttings can be planted in a well-draining soil mixture and kept moist until they root. Rooting should occur within three to four weeks.
Division can be performed on mature plants in the spring or fall. The plant should be dug up and the root ball separated into smaller sections. Each section should have a portion of the stem and some roots. The divided plants can be planted in a well-draining soil mixture and kept moist until they establish new roots.
Disease Management
Arabis arcuata (Nutt.) Gray var. rubicundula Jepson may be affected by various diseases that can lead to the plant's decline if not adequately managed. Here are some common diseases associated with this plant:
Anthracnose
Anthracnose is a fungal disease that can cause leaf spots, stem cankers, and wilting of the plant. The best management practice is to remove and destroy any infected plant material and ensure proper sanitation in the garden, such as avoiding overhead watering, which encourages the spread of the spores. Fungicide treatment may also be necessary.
Root Rot
Root rot is a disease caused by soil-borne fungi that can cause plant death. The fungus infects the roots, making them unable to absorb water and essential nutrients. To manage this disease, remove and destroy infected plants, ensure proper drainage, avoid overwatering, and use well-draining soil. Fungicide treatment may also be necessary.
Bacterial Canker
Bacterial canker is a bacterial disease that affects the stem tissue, causing cankers, wilting, and plant death. The disease can spread rapidly in wet and humid conditions. The best management practice is to remove and destroy infected plant material promptly. Copper-based fungicides can help prevent the spread of the disease.
Pest Management
Arabis arcuata (Nutt.) Gray var. rubicundula Jepson may also be affected by various pests. Here are some common pests associated with this plant and ways to manage them:
Cabbage Aphids
Cabbage aphids are small, soft-bodied insects that cluster on the stems and leaves of plants, causing distortion and stunting of growth. The best management practice includes spraying the plant with a strong jet of water to dislodge them. Alternatively, insecticidal soap or neem oil spray will kill them on contact.
Spider Mites
Spider mites are tiny pests that cause stippling of the leaves and yellowing of the plants. They are often challenging to detect as they are very small. The best management practice includes keeping the plant healthy and vigorous, maintaining proper watering practices, and using insecticidal soap or neem oil spray to kill them on contact.
Slugs and Snails
Slugs and snails chew irregular holes in the leaves of plants and can cause extensive damage if left unmanaged. The best management practice includes handpicking the pests, removing debris and weedy areas that provide shelter, and setting up barriers such as copper tape or diatomaceous earth around the plant base. Alternatively, bait traps can also be used.
