Origin
Phacelia divaricata (Benth.) Gray var. insularis (Munz) Munz, commonly known as Island phacelia, is a native plant of California. Its habitat ranges from the Channel Islands to the mainland along the coast and inland ranges.
Common Names
Island phacelia is known by several names, including Island bluecurls, island scorpion-weed, and island phacelia.
Appearance
Phacelia divaricata var. insularis is a perennial herb that grows up to 50 centimeters tall. The plant has a delicate but dense appearance, with finely dissected leaves that are green and hairy. The flowers are slender and tubular, with a pale lavender to blue color, and they grow in clusters at the top of the stems. The flowers are attractive to pollinators like bees and butterflies.
Uses
Phacelia divaricata var. insularis has limited uses, but it is grown as an ornamental plant. The plant is also used to control soil erosion and as a cover crop in land restoration projects due to its ability to improve soil quality and inhibit weed growth. Island phacelia is a drought-tolerant plant that can adapt to a variety of soil types, making it an ideal plant for conservation projects. This plant is not cultivated for food, medicine, or other purposes due to its low yield.
Light Requirements
Phacelia divaricata var. insularis grows best in full sun but can tolerate partial shade, especially in hot climates. In shaded areas, plants tend to become leggy and produce fewer flowers.
Temperature Requirements
This plant thrives in mild to warm temperatures ranging from 60°F to 80°F (15.5°C to 26.6°C). It can survive in temperatures as low as 20°F (-6.7°C) but may not produce flowers during colder months. In extremely hot temperatures, this plant may require more frequent watering.
Soil Requirements
Phacelia divaricata var. insularis prefers well-draining soils with a pH of 6.0 to 7.0. It can tolerate a wide range of soil types, including sandy, loamy, and clay soils, as long as they are well-draining. Soil should be amended with compost or organic matter before planting to improve soil fertility, water retention, and drainage.
Cultivation methods
Phacelia divaricata (Benth.) Gray var. insularis (Munz) Munz grows well in sandy, loamy, or clay soils and prefers full sun exposure. It can be propagated from seeds, which should be sown in the spring or fall. The seeds should be planted 1/4 inch deep, and the area should be kept moist until the seedlings emerge.
Watering needs
Phacelia divaricata (Benth.) Gray var. insularis (Munz) Munz requires moderate watering. It should be watered regularly during the growing season, about once a week, or when the top inch of soil feels dry to the touch. Avoid overwatering or leaving the soil waterlogged to prevent root rot.
Fertilization
Phacelia divaricata (Benth.) Gray var. insularis (Munz) Munz is a light feeder and does not require heavy fertilization. A balanced, all-purpose fertilizer can be applied once a month during the growing season. Avoid fertilizing during the winter or dormancy period.
Pruning
Phacelia divaricata (Benth.) Gray var. insularis (Munz) Munz does not require much pruning. However, deadheading the spent flowers can help prolong the blooming period. Any damaged or diseased branches should be removed immediately to prevent the spread of disease. Pruning can be done in late winter or early spring before the new growth appears.
Propagation of Phacelia divaricata var. insularis
Phacelia divaricata var. insularis, commonly known as the Island phacelia, is a native plant to California. It is a hardy, drought-tolerant plant that can be propagated through various methods depending on the grower's preference.
Seed Propagation
The easiest and most common method to propagate Phacelia divaricata var. insularis is through seed. The plant usually produces ample seed in the fall and can be collected at that time. Propagators can also purchase seeds from nurseries or online sources. Seeds should be sown in a well-draining soil mixture in the late fall or early winter and covered lightly with a thin layer of soil or vermiculite. The pots should be kept moist, but not too wet, and placed in an area with cool temperatures, around 60°F. Once the plants have developed their true leaves, they can be transplanted into larger pots or directly into the ground.
Division
Phacelia divaricata var. insularis can also be propagated through division. This is done by carefully digging up mature plants in the spring or fall and dividing the root ball into several sections. Each section should have some roots and at least one stem with foliage. The sections can then be transplanted into new pots or directly into the ground.
Stem Cuttings
While less common, Phacelia divaricata var. insularis can be propagated through stem cuttings. This method involves taking a cutting from a mature stem and placing it in a rooting hormone before planting it in a well-draining soil mixture. The cutting should be kept moist, but not too wet, and placed in an area with bright, indirect light. After a few weeks, roots should begin to develop, and the plant can be transplanted into a larger pot or directly into the ground.
Disease Management
Phacelia divaricata var. insularis is generally a disease-resistant plant. However, it can still get infected by certain diseases that can affect its growth and yield. The common diseases that can affect Phacelia divaricata var. insularis include:
Fungal Diseases
Some of the fungal diseases that can infect Phacelia divaricata var. insularis are powdery mildew, root rot, and damping-off. To manage these diseases, it is important to plant the seeds in well-drained soil and avoid overwatering. The use of fungicides can also be effective in controlling damp-off and root rot. Regular application of sulfur or fungicides can be effective in managing powdery mildew.
Bacterial Diseases
Bacterial diseases like bacterial blight and crown gall can also affect Phacelia divaricata var. insularis. Removing and destroying infected plants, avoiding overhead irrigation, and maintaining proper spacing between the plants can help manage bacterial blight. For crown gall, it is best to use planting material from disease-free plants, and avoid injury to plants that can promote infection by bacteria.
Pest Management
Phacelia divaricata var. insularis is susceptible to attacks by certain pests that can cause damage to the plant leaves, flowers, and stem. Some of the common pests that can affect Phacelia divaricata var. insularis include:
Aphids
Aphids are small, soft-bodied insects that can feed on the sap of Phacelia divaricata var. insularis causing deformation of leaves and stunted growth. The use of insecticidal sprays, sticky traps, or companion planting with predator insects like ladybugs and lacewings can be effective in controlling aphids.
Thrips
Thrips are tiny insects that feed on the leaves and flowers of Phacelia divaricata var. insularis. They can cause distortion of the leaves and flowers leading to reduced yield. The use of insecticidal soap or neem oil can be effective in controlling thrips.
Spider Mites
Spider mites are small arachnids that suck sap from the leaves of Phacelia divaricata var. insularis causing discoloration and defoliation. They thrive in hot and dry conditions, so ensure to keep the plant well-watered. The use of insecticidal soap, neem oil, or predatory mites can be effective in controlling spider mites.
Regular monitoring of the plant and implementing preventive measures can help manage pests and diseases effectively. It is important to use these management methods responsibly and ensure not to harm the environment or beneficial insects.
