Overview
Eriastrum sapphirinum (Eastw.) Mason ssp. dasyanthum (Brand) Mason, commonly known as the Mojave woollystar, is a herbaceous perennial plant in the family Polemoniaceae. The plant is primarily found in North America, specifically in the Mojave Desert region of California, Nevada, and Arizona.
Appearance
The Mojave woollystar is a small, bushy plant usually growing to 1-2 feet tall and 1-3 feet wide with a rounded or spreading habit. The plant has narrow, linear leaves that are an inch long or less and densely covered with silver-white hairs. The flowers have five vivid blue or violet petals, each about half an inch long, and a yellow center. The plant blooms from April to June.
Uses
The Mojave woollystar is an important species in desert habitats, providing food and cover for many animal species. It is also used in landscape restoration projects and as a drought-tolerant ornamental plant in gardens. The plant has no known medicinal uses.
Light Requirements
Eriastrum sapphirinum ssp. dasyanthum prefers full sun to partial shade. It can tolerate some shade but excessive shade can reduce flowering and overall growth.
Temperature Requirements
This plant is adapted to the Mediterranean climate and can tolerate both hot and cool temperatures. In general, it prefers temperatures between 60-80°F during the day and 40-60°F at night.
Soil Requirements
Eriastrum sapphirinum ssp. dasyanthum grows best in well-draining, sandy soils with a pH between 6.0-7.5. It can tolerate some salinity, but does not do well in heavy, clay soils. It is also adapted to nutrient-poor soils and fertilization is generally not necessary.
Cultivation methods
Eriastrum sapphirinum (Eastw.) Mason ssp. dasyanthum (Brand) Mason, commonly known as Mojave woollystar, is a charming, small perennial plant that is native to western North America. It requires full sun exposure and thrives in well-draining soils that are low in organic material. The ideal soil pH level should be between 6.5 and 7.5.
Mojave woollystar can be propagated through seeds or cuttings. Seeds can be sowed in early spring, and cuttings should be taken in late spring or early summer.
Watering needs
Although Mojave woollystar is drought-tolerant, it requires regular watering during the first growing season to establish a robust root system. After that, the plant can tolerate periods of drought, but it still requires regular watering to ensure it thrives. Water it deeply once or twice a week, depending on the soil’s moisture content and prevailing weather conditions.
Fertilization
Eriastrum sapphirinum (Eastw.) Mason ssp. dasyanthum (Brand) Mason does not require frequent fertilization. In fact, over-fertilization can be harmful to this plant. Apply a balanced, slow-release fertilizer once a year in early spring or late winter to facilitate new growth.
Pruning
Mojave woollystar requires minimal pruning. You can pinch back the stem tips when they reach approximately 4 inches to encourage branching and a fuller growth habit. Deadheading the spent flowers promptly can prolong blooming. Remember to keep the plant’s natural shape while pruning and avoid drastically cutting back the foliage.
Propagation of Eriastrum sapphirinum ssp. dasyanthum
Eriastrum sapphirinum ssp. dasyanthum can be propagated through seeds, cuttings, and division.
Seeds
The seeds of Eriastrum sapphirinum ssp. dasyanthum can be collected from mature seed capsules in the fall. The seeds can be sown in pots or seed trays filled with well-draining soil in the fall or early spring. The seeds need to be lightly covered with soil and kept moist until germination occurs, which typically takes around 7 to 21 days. After germination, the seedlings can be transplanted into individual pots or directly into the ground.
Cuttings
Eriastrum sapphirinum ssp. dasyanthum can also be propagated through cuttings. The ideal time to take cuttings is in the early summer when the plant is actively growing. Select a healthy shoot and cut a 3-4 inch section just below a node. Remove the leaves from the bottom half of the cutting and dip the end in rooting hormone. Plant the cutting in a pot filled with well-draining soil and water thoroughly. Keep the soil moist and the cutting in a shaded area until it roots, which takes about 4-6 weeks. After the cutting has rooted, it can be transplanted into individual pots or directly into the ground.
Division
Eriastrum sapphirinum ssp. dasyanthum can also be propagated through division. Divide the plant in the spring or early fall when the plant is not actively growing. Use a sharp knife or garden spade to separate the plant into smaller sections, each with its own root system. Replant each section in its own pot or in the ground, and keep the soil moist until the plant becomes established.
Disease Management
Eriastrum sapphirinum ssp. dasyanthum is a relatively disease-resistant plant. However, it can still be affected by diseases such as powdery mildew and root rot.
Powdery mildew is a fungal disease that appears as a white powdery substance on the leaves and stems of the plant. It can be treated by removing the affected parts and applying a fungicide. It is important to maintain good air circulation around the plant to prevent powdery mildew from spreading.
Root rot is a disease caused by fungi that attack the roots of the plant. It can be prevented by ensuring that the soil is well-drained and not overwatered. If root rot is already present, the affected plant must be removed to prevent the disease from spreading to other plants.
Pest Management
Eriastrum sapphirinum ssp. dasyanthum can also be affected by pests. The most common pests that attack this plant are spider mites and thrips.
Spider mites are tiny pests that can cause extensive damage to the plant by feeding on its leaves. They can be controlled by using an insecticidal soap or oil spray. It is also important to maintain good air circulation around the plant to prevent spider mites from spreading.
Thrips are small, slender insects that feed on the leaves and flowers of the plant. They can be controlled by using insecticidal soap or oil spray. It is important to keep the plant well-watered and well-fertilized to prevent thrips infestation.
