Origin and Common Names
Androsace septentrionalis L. var. subumbellata A. Nels., commonly known as the Northern Rock Jasmine or the Umbellate Androsace, is a flowering plant that belongs to the Primulaceae family. The plant is native to the Arctic and alpine regions of North America, specifically in Alaska, Canada, and the Rocky Mountains of the United States.
Appearance
The Umbellate Androsace is a low-growing perennial plant that typically measures around 5 to 15 centimeters in height. The plant produces basal leaves that are arranged in a rosette formation. The leaves are small, elliptic to spatulate-shaped, and may measure around 1 to 2.5 centimeters in length.
The plant produces small, white to pinkish flowers that are arranged in umbel-like inflorescences. The flowers measure around 3 to 6 millimeters in diameter and have five lobes. The flowering season of the plant usually occurs between May to September.
Uses
The Umbellate Androsace is primarily used for ornamental purposes. The plant is a popular choice for rock gardens, alpine gardens, and other similar landscaping projects. It is also commonly used as a ground cover in areas with poor soil conditions.
In traditional medicine, the plant's leaves are used to treat coughs, colds, and respiratory problems. The plant is also said to have anti-inflammatory and analgesic properties.
Light Requirements
The Androsace septentrionalis L. var. subumbellata A. Nels. typically grows best in full sun to partial shade conditions. It can tolerate low light conditions but may not grow as well or produce as many flowers. Too much direct sunlight can cause leaf scorching, so it is best to provide some shade during the hottest part of the day if growing in full sun conditions.
Temperature Requirements
The Androsace septentrionalis L. var. subumbellata A. Nels. is a cool-season plant and prefers cool temperatures ranging from 40 to 70 degrees Fahrenheit. It can tolerate some frost, and in fact, exposure to colder temperatures promotes flower production. At high temperatures, the plant may wilt and fail to produce flowers.
Soil Requirements
The Androsace septentrionalis L. var. subumbellata A. Nels. grows best in well-drained soils that are rich in organic matter. The ideal soil pH for this plant is neutral to slightly acidic, ranging from 6.0 to 7.0. The plant may not tolerate waterlogged soils and may develop root rot if the soil is too wet. It is best to avoid sandy soils or soils that are too compacted as they may not provide the necessary nutrients and support for the plant to grow and thrive.
Cultivation Methods
Androsace septentrionalis L. var. subumbellata A. Nels., commonly known as Northern rock-jasmine, has a preference for cool, moist, and well-draining soils. This plant grows best in partial shade or full sun depending on the region and requires protection from strong winds. The ideal temperature range for growing rock-jasmine is between 15°C-24°C.
Watering Needs
Rock-jasmine prefers moist soil, but overwatering can cause root rot. It is essential to monitor the moisture level of the soil and water plants when the soil starts to feel dry. During hot and dry weather, plants may require watering every two to three days. However, during winter, when the plant is dormant, it requires less water.
Fertilization
Androsace septentrionalis L. var. subumbellata A. Nels does not require heavy fertilization. During the plant's active growth phase, a balanced fertilizer (10-10-10) can be applied once every two weeks. Avoid using fertilizers that contain high levels of nitrogen, as this can lead to excessive leaf growth rather than flower production.
Pruning
Periodic maintenance pruning is recommended for rock-jasmine. During the early spring season, after flowering, remove any dead, damaged, or diseased leaves and stems. Pinching back new shoots can encourage the plant to produce a denser growth habit.
Propagation of Androsace Septentrionalis L. var. Subumbellata A. Nels.
Androsace Septentrionalis L. var. Subumbellata A. Nels can be propagated through various methods. Some of the prominent methods are:
Vegetative Propagation
Vegetative propagation refers to the process of reproducing plants through the use of their vegetative parts. In the case of Androsace Septentrionalis L. var. Subumbellata A. Nels., it can be propagated through the division of its root system, rhizomes or stem cuttings.
In order to propagate the plant through stem cuttings, the gardener must select a healthy stem from the Androsace plant. The stem should be at least two inches long with one or two leaves attached to it. Remove any flowers or buds from the stem tip and plant the stem in a soilless mixture. Keep the soil moist, and in a few weeks, the plant will start developing roots. Once it has well-established roots, the Androsace plant can be transplanted to a container filled with a well-draining soil mixture.
Seed Propagation
The most common method of propagating Androsace Septentrionalis L. var. Subumbellata A. Nels. is through seed propagation. The plant produces small, light-colored seeds that are easily collected. The seeds can be allowed to self-sow in the garden, or they can be collected and stored in a cool, dry place.
If the gardener decides to propagate the plant through seed, it should be sown during the early spring or fall. The seed should be planted in a soilless mixture, and should not be covered as the seeds are very small. Place the container in a well-lit area and keep the soil moist. Germination should occur in 2-4 weeks. Once the seedlings have developed a few true leaves, they can be transplanted into separate containers filled with a well-draining soil mix.
Cuttings Propagation
Cuttings propagation is another method of reproducing Androsace Septentrionalis L. var. Subumbellata A. Nels. This method involves taking a stem or leaf cutting from a mature plant and rooting it to produce a new plant. This technique is usually successful when it is carried out during the growing season, when the plant’s tissue is less woody.
To carry out this method, choose a healthy stem or leaf from the plant and cut it from the parent plant. Remove any flowers or buds from the cutting. Place the cutting in a rooting hormone and plant in a soilless mix. Ensure that the soil is moist and keep it in a well-lit area. The cutting will root in a few weeks and can be transplanted into its own container with well-draining soil mix.
Disease Management
Androsace septentrionalis L. var. subumbellata A. Nels. is generally a hardy plant, but some common diseases might affect it. Here are some of the diseases and ways to manage them:
- Fungal leaf spots: This disease appears as small brownish-black spots on the leaves. The spots can merge, sometimes causing the leaves to turn yellow and fall off. To manage fungal leaf spots, remove the affected leaves and debris near the plant, avoid overhead watering, and apply a fungicide according to the manufacturer's instructions.
- Powdery mildew: Powdery mildew is a fungal infection that appears as a white, powdery coating on the leaves. To manage powdery mildew, prune infected areas and dispose of the pruned parts carefully, and apply fungicide according to the manufacturer's instructions.
- Crown rot: Crown rot is a fungal disease that typically affects the roots of the plant, causing stunted growth, yellowing of the leaves, and wilting. The best way to manage crown rot is to practice good soil drainage and avoid overwatering. You should also remove affected plants to prevent the disease from spreading.
Pest Management
Androsace septentrionalis L. var. subumbellata A. Nels. is an attractive plant and as such can attract pests. Here are some common pests that could affect the plant and ways to manage them:
- Aphids: Aphids are small green insects that feed on the sap of the plant, causing leaves to curl and turn yellow. To manage aphids, spray the plant with an insecticidal soap or neem oil.
- Spider mites: Spider mites are tiny insects that are difficult to see. They can cause the leaves to turn yellow and lose their vigor. To manage spider mites, spray the plant with water, or use an appropriate miticide according to the manufacturer's instructions.
- Snails and slugs: These pests can damage the leaves and stems of the plant. To manage them, handpick them and dispose of them, or use a slug bait that contains iron phosphate.
