Overview
Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén is a herbaceous plant and a subspecies of the Rorippa islandica species belonging to the Mustard family (Brassicaceae). The plant is mostly found in North America, particularly in Canada and the United States.
Common Name
The common name of Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén is Island Watercress.
Appearance
Island Watercress is a slender aquatic plant, with stems that usually have a reddish hue and can grow up to 60 centimeters in length. The leaves are lobed and can be up to 10 centimeters in length. The flowers are small and white in color, born in elongated racemes. The plant produces small, oval seeds that are dispersed by water.
Uses
Traditionally, the leaves and stems of Island Watercress have been used as a salad green and medicinal herb. Island Watercress, like other watercress species, contains high levels of vitamin C and minerals, making it a nutritious addition to meals. It is also believed to promote digestion and liver function.
Island Watercress also plays a vital ecological role by providing a habitat and food source for various aquatic species such as fish, insects, and birds. Additionally, the plant is often used in fishponds and aquaponics systems to help maintain water quality.
Growth conditions of Rorippa islandica ssp. fernaldiana
Rorippa islandica ssp. fernaldiana, also known as Fernald's watercress, is a small aquatic or semi-aquatic plant that grows in wetlands, swamps, and marshes. It is commonly found in the northeastern region of North America, specifically in Maine, Massachusetts, New Hampshire, and Vermont.
Light requirements
Rorippa islandica ssp. fernaldiana requires full or partial sunlight to grow properly. It needs at least four hours of direct sunlight per day to thrive. Without enough sunlight, the plant may become weak and stunted.
Temperature requirements
The ideal temperature range for Rorippa islandica ssp. fernaldiana is between 10°C and 25°C. The plant can tolerate a wide range of temperature fluctuations, but extreme cold or heat can be detrimental to its growth. In colder regions, the plant may start to die back in late fall and remain dormant until spring.
Soil requirements
Rorippa islandica ssp. fernaldiana prefers wet, muddy, or sandy soils that are rich in nutrients. The soil should also be neutral to slightly acidic with a pH range between 6.0 and 7.5. The plant also requires a constant supply of water to support its growth, making it well-suited to wet soils found in marshes and wetlands. Good drainage is also important to prevent the soil from becoming waterlogged.
Cultivation Methods
Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén thrives well in moist to wet soil conditions and favors direct sunlight. The plant requires well-draining soils and can survive in conditions where the pH ranges from neutral to mildly acidic. The species can grow in various soil types, including clay, sand, loam, and gravelly soils.
Watering Needs
Being a wetland plant, Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén requires consistent moisture for optimal growth. The species can tolerate periodic flooding, but in dry conditions, ensure to supplement with regular watering to ensure that the soil remains wet. Water the plant weekly, and in case of extended periods without rainfall, increase the watering frequency.
Fertilization
Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén is a low maintenance plant that requires minimal fertilization. To promote growth and enhance flowering, either apply slow-release fertilizer in early spring or incorporate a complete fertilizer mix into the soil during planting. However, the plant can do without the fertilization, especially in nutrient-rich soils.
Pruning
Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén does not require regular pruning, mainly when grown in naturalized settings. However, you can trim the plant to remove wilted, yellowing, or dead leaves. Besides, removing the spent flowers prevents the plant from reseeding in the growing area.
Propagation of Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén
Propagating Rorippa islandica (Oeder) Borbás ssp. fernaldiana (Butters & Abbe) Hultén can be achieved through different methods including seed propagation, stem cuttings, and division.
Seed propagation
The easiest method of propagating Rorippa islandica is using seeds. Sow the seeds in well-draining soil in a seedling tray or pots in fall or spring. Ensure the soil is moist and well-aerated to ensure the seeds germinate and take hold. The ideal temperature range for germination is between 10°C and 20°C. The seedlings should be watered regularly and transplanted when they are strong and healthy.
Stem cuttings
Rorippa islandica can also be propagated through stem cuttings. Take cuttings with a sterilized blade from healthy and vigorous mature plants, about 5-10cm in length. Remove the lower leaves and plant the cutting in a well-draining substrate, keeping it moist until it roots. A rooting hormone may be used to promote rooting.
Division
Division is also an efficient method of propagating Rorippa islandica. Divide mature plants during the growing season, ensuring each division has a healthy root and foliage. Transplant the divisions into well-draining soil, watering them frequently to encourage growth and development.
Regardless of the propagation method chosen, ensure the planting location is appropriate to ensure the survival of the newly propagated Rorippa islandica.
Disease Management
Rorippa islandica ssp. fernaldiana is generally a healthy plant with few disease issues. However, it may be susceptible to some diseases that may decrease its vigor and crop yield if not managed properly.
One of the most common diseases affecting this plant is the fungal disease leaf spot, which appears as circular or angular lesions on the leaves, causing them to turn yellow and eventually drop off the plant. To manage this disease, prompt removal of the infected leaves and debris from the plant and pruning the affected areas can help reduce the progression of the disease. In severe cases, fungicides may be applied before the disease gets out of control.
Another common disease of Rorippa islandica ssp. fernaldiana is powdery mildew, which is a fungal disease that can cause a white, powdery coating on the leaves and stems, leading to stunting and deformation of the plant. Cultural practices such as avoiding overhead watering, improving air circulation around the plant, and applying fungicides can help reduce this disease occurrence.
Pest Management
Rorippa islandica ssp. fernaldiana is generally resistant to common pests. However, some pests can cause damage to the plant if not managed effectively.
One of the most common pests affecting this plant is the cabbage aphid, which feeds on the leaves, causing yellowing and distortion. To manage this pest, regular monitoring of the plant and removal of the affected areas can help reduce its numbers. Insecticidal soaps and oils can also be used to control the aphids if their numbers are too high.
Another pest that can affect Rorippa islandica ssp. fernaldiana is the flea beetle, which feeds on the foliage, causing small holes that can reduce the plant's growth. To manage this pest, row covers can be used to exclude the beetles, and insecticides can be applied to the plant during the early stages of infestation.
Lastly, the plant can be attacked by slugs and snails, which can cause damage to the plant's leaves and stems. To manage this pest, barriers such as copper tapes and snail baits can be used to repel or kill the pests.
