Description of Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe
Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe is a perennial plant, belonging to the Brassicaceae family. It is commonly known as Fernald's watercress, Islandica cress, or Arctic cress.
Origin
Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe is native to arctic and sub-arctic regions of North America. It is found in Alaska, Greenland, Canada, and Northern United States.
Appearance
The plant has a rosette growth habit and grows up to 30 cm in height. It has yellow flowers that are 4-6 mm in diameter and bloom from June to August. Fernald's watercress has green, fleshy, and deeply lobed leaves that are 1-4 cm long, 1-3 cm wide, and are arranged opposite to each other.
Uses
Fernald's watercress is edible and is used in salads or as a garnish. It has a slightly peppery taste and is high in vitamin C. The plant is also used as a medicinal herb in traditional medicine for treating various ailments like scurvy, coughs, and colds. In addition, it is used as an ornamental plant in gardens and landscapes.
Overall, Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe is a beautiful and useful plant with various applications.Growth Conditions of Rorippa islandica var. fernaldiana
Rorippa islandica var. fernaldiana, a subspecies of the northern cress, is predominantly found in the northeastern part of North America. This plant species is known for its beautiful yellow flowers and rich green leaves.
Light Requirements
The Rorippa islandica var. fernaldiana plant species prefers to grow in full sunlight or partial shade. Therefore, it is ideal to place them in an area where there is enough exposure to sunlight. However, during high temperature seasons, partial shade may be needed to prevent the foliage from drying up.
Temperature Requirements
Rorippa islandica var. fernaldiana prefers a cool and moderately moist climate. The plant is hardy to low temperatures and prefers the temperature range between 10°C to 25°C (50°F to 77°F) to thrive. Exposure to extreme heat can cause the plant to wilt and dry out, while long-term exposure to cold can lead to stunted growth.
Soil Requirements
These plants prefer a neutral to slightly acidic soil, with a pH range of 5.5 to 7.0. Rorippa islandica var. fernaldiana prefers well-drained soils that can hold moisture but do not become waterlogged. It is crucial to avoid heavy clay and sandy soils, which are not favorable for the growth of this plant. A mixture of organic matter, sand, and loam will be perfect for optimum growth.
Cultivation Method
Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe typically grows in soils that are moist, rich in organic matter, and acidic. The plant requires full to partial sunlight for proper growth. It can be propagated from seeds or cuttings. If you are cultivating it from seeds, then sow the seeds in early spring in a seed tray containing a mix of peat moss and sand.
Watering Needs
Water the Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe regularly to maintain soil moisture. It thrives in constantly moist soil. You should water the plant to keep the soil moist but avoid overwatering as it may lead to root rot.
Fertilization
The Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe requires regular fertilization to support growth. Use a slow-release or liquid fertilizer with a balanced ratio of Nitrogen, Phosphorus, and Potassium (NPK) every two weeks during the active growing season, which is from spring to early fall.
Pruning
Pruning is not necessary for Rorippa islandica (Oeder) Borbás var. fernaldiana Butters & Abbe. However, you can trim back any wilted or yellowed leaves or any dead or damaged stems as needed. Trimming can help keep the plant neat and stimulate new growth.
Propagation of Rorippa islandica var. fernaldiana
The propagation of Rorippa islandica var. fernaldiana is generally done through seeds. The plant is a short-lived perennial and produces a large number of seeds that can be collected and sown in containers or directly in the garden.
Seed Collection
The seeds of Rorippa islandica var. fernaldiana are ready for collection in the late summer or early fall. The seed pods will turn brown and dry, and the seeds can be easily shaken out of the pods. It is recommended to collect the seeds before they disperse naturally.
Seed Stratification
Seed stratification is necessary for Rorippa islandica var. fernaldiana to germinate successfully. The seeds need to be exposed to a period of cold temperatures (around 4°C) for several weeks to break dormancy and promote germination. This process is called stratification and can be achieved by storing the seeds in a moist medium, such as peat moss or vermiculite, in the refrigerator.
Seed Sowing
Rorippa islandica var. fernaldiana seeds can be sown in containers or directly in the garden. If sowing in containers, use a well-draining soil mix and place the containers in a bright, but not direct, light. Keep the soil moist but not waterlogged. If sowing directly in the garden, prepare the soil by removing all weeds and debris, and lightly rake the surface. Scatter the seeds evenly and cover with a thin layer of soil.
Seedling Care
Once the seeds have germinated and the seedlings have emerged, it is essential to keep them moist. Avoid overwatering, which can cause damping-off disease. When the seedlings are big enough to handle, thin them out to ensure that they have enough space to grow.
Disease Management
Due to its natural habitat in wet and moist environments, Rorippa islandica var. fernaldiana is susceptible to fungal and bacterial diseases such as downy mildew, powdery mildew, and bacterial leaf spot.
To manage these diseases, it is important to practice good sanitation measures. This includes removing and disposing of infected plant materials, avoiding overhead watering, and providing adequate spacing between plants to promote air circulation.
Fungicides and bactericides may also be used as a preventative measure, but should be used with caution and according to label instructions. It is also important to rotate these products to prevent the development of resistant strains of the pathogens.
Pest Management
The main pests that may affect Rorippa islandica var. fernaldiana are aphids and flea beetles.
Aphids can be controlled through natural predators such as ladybugs and lacewings, or through application of insecticidal soap or oil. It is important to monitor populations regularly to ensure early detection and treatment.
Flea beetles can be managed through physical barriers such as row covers, or through the use of insecticides. It is important to rotate these products to prevent the development of resistant strains in the pest population.
Overall, a combination of preventative measures such as sanitation practices and natural predators, and targeted use of pesticides can help to effectively manage disease and pest issues in Rorippa islandica var. fernaldiana.
