Origin
Phacelia exilis (Gray) G.L. Lee, commonly known as slender phacelia, is a species of flowering plant indigenous to North America, specifically in the western parts of the United States and Canada. It is commonly found in the intermontane deserts, valleys, and mountains of the Western United States and British Columbia.
Common Names
The slender phacelia has various common names, including the mountain phacelia, slender scorpion-weed, and wild heliotrope.
Uses
Phacelia exilis has a wide range of uses. Its flowers produce nectar that can be consumed by honeybees, making it a valuable plant in apiculture. It is also used in traditional medicine to treat ailments such as rheumatism, pneumonia, and coughs. Some Native American tribes have also used the plant to aid in childbirth.
General Appearance
The Phacelia exilis plant has an erect stem that grows up to 30 cm tall. The plant's leaves are lobed, with the lower leaves being deeply lobed, and the upper leaves becoming less lobed. The flowers are arranged in a distinctive coiled inflorescence, with each flower being about 6-8 mm in length. The flowers are generally blue or purple in color, but can sometimes appear pink or white. The fruit produced by the plant is a capsule that contains small seeds. The slender phacelia blooms from March to July.
Light Requirements
Phacelia exilis prefers moderate to full sunlight exposure. A minimum of 4-5 hours of sunlight each day is optimal for cultivation. If planted in partial shade, the plant may become tall and spindly with fewer flowers. However, in regions with hot summers, some shade during the hottest part of the day may be necessary to prevent damage to the plant.
Temperature Requirements
The plant can tolerate a wide range of temperatures, including extreme heat and cold. Optimal growth occurs at temperatures ranging from 15-25°C (59-77°F). Prolonged exposure to temperatures above 30°C (86°F) can cause the plant to stop flowering and to wilt. Frost can damage the plant, but it can recover well after the frost has subsided.
Soil Requirements
Phacelia exilis requires well-draining soils with a pH range of 6.0-7.5. It can grow well in sandy, loamy, or clay soils, as long as the soil is well-draining. The plant prefers soil that is rich in organic matter, so the addition of compost or other organic matter is recommended. The roots of the plant are shallow, so it is important to avoid compacted soils. Overly wet soil can lead to issues such as root rot, so careful watering practices are recommended.
Cultivation
Phacelia exilis is a hardy plant that requires a sunny location and well-drained soil. It can grow in various soil types, but it prefers sandy loam. The plant can grow up to 1-2 feet tall and should be spaced at least 6-12 inches apart. The seeds can be sown directly into the ground, in early spring when the soil has warmed up.
Watering needs
The Phacelia exilis is drought tolerant and requires little water once established. However, consistent moisture is necessary for successful germination. Water the soil when the top inch is dry, but avoid overwatering as this may cause root rot and other diseases.
Fertilization
This plant does not require frequent fertilization as it grows well in poor soils. However, a small amount of balanced fertilizer can be applied once or twice during the growing season to enhance growth and flowering. Overfertilizing can lead to excessive foliage growth and fewer flowers.
Pruning
Phacelia exilis does not require much pruning. You can cut the flowers for arrangements without affecting the growth of the plant. Deadheading can help to prolong the blooming season, and it's best to cut back the entire plant after the flowering period is over. This will prevent self-sowing and promote bushier growth.
Propagation of Phacelia exilis
Phacelia exilis (Gray) G.L. Lee, commonly known as the Mountain Phacelia is a silvery-green, densely hairy annual herb that belongs to the borage family. It is native to the western United States, including California, Arizona, and Nevada. The plant grows up to 1-4 in. (2.5-10 cm) in height and produces blue or purple flowers in clusters.
Propagation Methods
The propagation of Phacelia exilis can be done through both seed and vegetative means. Here are two most common methods of propagation:
Seed Propagation
Phacelia exilis can be propagated through seeds. The seeds are small and black. Collect the seeds from mature plants in the summer after the flowers have bloomed and the seed pods have dried out. Sow the seeds in a well-draining seed-starting mix in fall or early spring. Seeds should be approximately 1/16 inch (1.5 mm) deep and spaced 1 inch (2.5 cm) apart. Keep the soil moist and at a temperature of approximately 60-70°F (15-21°C). Germination typically occurs in 7-14 days.
Vegetative Propagation
Vegetative propagation is another method of producing new plants of Phacelia exilis. Stems cuttings from mature plants can be rooted in seed-starting mix under high humidity and warm temperature conditions. Once rooted, the cuttings can be transplanted into individual pots or directly into the garden bed. It is important to keep the soil moist and out of direct sunlight until the plants have established roots.
Disease Management
Phacelia exilis is generally healthy and resistant to most diseases. However, it may be affected by fungal infections causing leaf spots, powdery mildew, and root rot. To prevent and manage these diseases, follow these tips:
- Plant in well-drained soils to avoid waterlogging, a common cause of root rot.
- Water at the base of the plant, avoiding wetting the foliage, as this can promote fungal growth.
- Avoid overhead watering or irrigation during humid weather conditions.
- Remove and destroy any infected plant debris and keep a clean garden to prevent the spread of disease.
- Apply fungicides as recommended when necessary.
Pest Management
Phacelia exilis may attract pests, including thrips, aphids, and spider mites. Here are some ways to manage these pests:
- Use beneficial insects, such as ladybugs and lacewings to control thrips and aphids.
- Maintain good garden hygiene and remove any weed growth around the plant to minimize hiding places for pests.
- Use insecticidal soaps and oils as an effective and organic way to control spider mites and aphids.
- Avoid using broad-spectrum insecticides, as they may also harm beneficial insects in the garden.
