Origin
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry, commonly known as Henderson's phlox, is a plant that belongs to the family Polemoniaceae. This plant is native to North America, specifically found in the western part of the continent, from British Columbia to California.
Common Names
Besides Henderson's phlox, this species of plant is also known by other common names, including Douglas' phlox and Henderson's prairie phlox.
Uses
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry is grown for ornamental purposes, particularly in gardens or as a border plant. The plant produces small, fragrant, and brightly-colored flowers that bloom in summer, attracting various pollinators such as bees and butterflies. Additionally, the plant has medicinal uses, specifically as a remedy for rheumatism and respiratory problems.
General Appearance
The plant typically grows up to 10 cm tall and prefers to grow in well-drained soil in a sunny area. The leaves are narrow and lance-shaped, while the flowers are small, with a diameter of 2.5 cm, and come in a variety of colors, including pink, purple, and lavender. The plant has a spreading growth habit and is drought tolerant, making it suitable for growing in a variety of settings.
Light Requirements
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry typically grows well in areas with full sun or partial shade. In areas with hot summers, the plant may benefit from some shade during the hottest parts of the day.
Temperature Range
This plant species can tolerate a wide range of temperatures. It primarily grows in USDA hardiness zones 5-9 and can withstand temperatures as low as -20°F (-28°C) and as high as 100°F (38°C).
Soil Requirements
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry prefers well-draining soils that are rich in organic matter. It can tolerate a pH range of 6.0 to 7.5. In areas with heavier soils, amending the soil with sand or other organic material can improve drainage.
Cultivation methods
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry, commonly known as Douglas phlox, grows best in well-drained soil with a neutral to slightly alkaline pH level. Choose a location that receives full sun to partial shade. It's crucial to plant Douglas phlox in an area with good air circulation to prevent powdery mildew.
Watering needs
Douglas phlox requires regular watering, especially during the dry months. Keep the soil evenly moist, but avoid overwatering the plant, which can lead to root rot. Water the plant at the base to prevent wetting the leaves, which can promote powdery mildew.
Fertilization
Fertilize Douglas phlox once a year during the early spring with a balanced fertilizer. Avoid applying too much nitrogen, which can encourage lush growth and make the plant more susceptible to diseases.
Pruning
Deadhead the spent flowers regularly to encourage more blooms and a neater appearance. Cut back the stems by up to half their length in early summer to promote bushier growth and discourage legginess. Avoid pruning too late in the season, as it may remove the plant's flower buds for next year.
Propagation of Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry is propagated through both seed and vegetative methods. The plant propagation can take place during the spring or early fall.
Seed Propagation
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry can be propagated by seeds. The seeds should be sown in a medium that is well-drained and moist. The soil pH should be around 6.5 to 7.5. The seeds should be sown at a depth of approximately 0.5 cm and lightly covered with soil. After sowing, the soil should be kept moist by spraying water. The seeds should germinate within 2 to 3 weeks.
Vegetative Propagation
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry can also be propagated vegetatively. This method involves taking cuttings from the mother plant and rooting them in a rooting hormone. The cuttings should be taken during the spring or early fall. The cuttings should be approximately 7.5 to 10 cm long and should have at least three nodes. The cuttings should be rooted in a soilless medium that is well-drained and moist. After rooting, the cuttings should be transplanted to a well-drained soil mixture and kept moist until they are well-established.
Disease Management
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry is susceptible to a range of diseases that can cause significant damage to the plant. Some of the most common diseases include powdery mildew, rust, leaf spot, and stem canker.
Powdery mildew is a type of fungal disease that appears as a white, powdery substance on the leaves and stems of the plant. To manage this disease, it is recommended to apply fungicides, such as sulfur, neem oil, and potassium bicarbonate. Additionally, proper plant spacing and ventilation can help reduce humidity levels and prevent the growth and spread of powdery mildew.
Rust is another common fungal disease that affects the leaves of Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry, causing yellowish-orange or brownish spores to appear on the underside of the leaves. To manage rust, remove and dispose of infected plant material immediately. Additionally, fungicides may be used to reduce the spread of the disease.
Leaf spot is a fungal disease that causes circular or irregular-shaped spots on the leaves of the plant. To manage leaf spot, remove and destroy infected leaves and apply fungicides as necessary. It is also important to ensure proper plant spacing and avoid overhead watering.
Stem canker is a fungal disease that causes the stem of the plant to develop sunken areas or lesions. To manage stem canker, remove infected plant material and use fungicides to prevent the disease from spreading to healthy plants.
Pest Management
Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry is also susceptible to a range of insect pests that can cause damage to the plant, including aphids, spider mites, and thrips.
Aphids are small, soft-bodied insects that feed on the leaves and stems of the plant. To manage aphids, apply insecticidal soap or neem oil to the affected plant parts. Additionally, natural predators, such as ladybugs and lacewings, can help control the population of aphids.
Spider mites are tiny, yellow or green insects that create fine webs on the leaves of the plant. To manage spider mites, apply insecticidal soap or neem oil to the affected plant parts and ensure proper plant spacing and ventilation.
Thrips are small, slender insects that feed on the flowers and leaves of the plant. To manage thrips, apply insecticidal soap or neem oil to the affected plant parts and remove and destroy infected plant material.
Regular inspection and monitoring of the plant can help identify and manage pest problems before they become severe and cause significant damage to Phlox douglasii Hook. ssp. hendersonii (E. Nels.) Wherry.
