Origin and Common Names
Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry, commonly known as the Western Showy Phlox or Lewis’s phlox, is a flowering plant species from the Polemoniaceae family. The native range of Phlox speciosa Pursh ssp. occidentalis is from the western United States, specifically in California, Oregon, and Washington.General Appearance
The Western Showy Phlox has a clump-forming habit and grows up to a height of 20-60 cm. The plant’s stem is slender and often hairy near the base. The leaves are lance-shaped, arranged opposite each other, and can grow up to 10 cm in length. The flowers are arranged in terminal clusters, and each cluster contains numerous pink or lavender-colored flowers. The petals are fused at the base and spread into a five-lobed corolla, which is up to 2-4 cm in diameter. The plant blooms from July to August and produces fruits that contain several seeds.Uses
The Western Showy Phlox has several uses. The plant’s flowers are attractive and are widely cultivated in gardens and landscapes. They are used for decoration purposes, and their sweet fragrance makes them ideal for cut flowers. The Western Showy Phlox is also used in wildflower restoration projects and is regarded as an essential plant species in several natural habitats. Additionally, the plant is used for medicinal purposes by several indigenous tribes in the Western United States to treat sore throats and swollen glands.Light
Phlox speciosa Pursh ssp. occidentalis thrives in full sun to partial shade. However, it requires at least 6 hours of sunlight daily to bloom properly. Too much shade can result in leafy growth instead of flowering.
Temperature
The plant prefers a moderate climate with temperatures ranging from 60°F to 80°F. It can tolerate cold temperatures up to 20°F but may suffer damage if exposed to frost for an extended period. In contrast, too much heat can cause the plant to wilt and dry out.
Soil Requirements
Phlox speciosa Pursh ssp. occidentalis favors well-drained soil that is rich in organic matter. The plant can tolerate a slightly acidic to neutral soil pH of 5.5 to 7.5. However, it cannot thrive in heavy clay soil that retains water or soil that is too sandy and dries out quickly. It is also essential to avoid poorly-draining soil that can lead to root rot.
Therefore, it is recommended to amend the soil with compost or well-rotted manure before planting the Phlox speciosa Pursh ssp. occidentalis.
Cultivation
Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry is a native plant to North America, which can be found from Montana to New Mexico. The species loves the sun and grows well in an environment with good air circulation. It is essential to prepare a well-draining soil, preferably sandy and acid to neutral (pH 6.0-7.0), to cultivate Phlox.
When planting, it is ideal to space each plant about 15-18 inches apart to give room for spreading. The plant can be planted in the fall or spring. It is also possible to propagate the plant using stem cuttings.
Watering needs
Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry requires an adequate water supply to grow lush and healthy. Regular watering is essential, especially during the growing season, which is usually in the summer. The plant requires about 1-2 inches of water every week, and it is best to water in the morning to prevent diseases such as powdery mildew.
By observing the plant, watering can be adjusted to meet its needs. Watering should be reduced in the fall as the plant prepares to go dormant in winter.
Fertilization
Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry requires fertilization to thrive correctly. The plant can be fertilized in the spring using a balanced fertilizer (10-10-10) to promote healthy growth. Fertilization can be repeated in the fall to prepare the plant for winter.
Over-fertilization should be avoided as it can lead to an overgrowth of foliage, reducing the plant's bloom. The best approach is to follow the manufacturer's instruction on the fertilizer pack and apply it accordingly.
Pruning
Pruning is essential for maintaining the health of Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry. Pruning should be done in late fall after the plant has finished blooming. Deadheading should be done as the blooms fade to promote more flowers.
The plant should also be cut back by about one-third to one-half of their height to prevent stem elongation and to encourage a bushier growth habit.
Propagation of Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry
Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry, also known as western prairie phlox, can be propagated through three primary methods: seed, division, and stem cuttings.
Seed Propagation
Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry produces numerous tiny seeds that can be collected in the fall and stored until spring. Seeds should be sown in flats indoors, kept moist, and exposed to light to encourage germination. After the seedlings have developed their second set of leaves, they can be transplanted to individual pots. Once the threat of frost has passed, they can be planted outdoors.
Division Propagation
The most straightforward method of propagating Phlox speciosa Pursh ssp. occidentalis (Dur. ex Torr.) Wherry is through division. This technique involves digging up mature plants in the fall while they are still in active growth and dividing the clumps into several smaller sections, each with their own roots and stems. Replant the divisions at the same depth as their original location.
Stem Cutting Propagation
The final method of propagation involves taking cuttings from new green growth, which should be done in early summer. Cuttings should be taken from stems near the base of the plant and treated with rooting hormone before placing them in a mixture of sand and peat moss. Cuttings should be kept moist, and within several weeks, they should start to develop roots and new growth. Once rooted, they can be transplanted to individual pots and eventually planted outdoors.
Common Diseases of Phlox speciosa Pursh ssp. occidentalis
Phlox speciosa Pursh ssp. occidentalis is susceptible to various diseases caused by fungal pathogens, including stem rot, powdery mildew, leaf spot, and root rots. The fungal pathogens thrive in moist soil environments, especially in warmer conditions, which can weaken the plant and cause the leaves and stems to rot, eventually leading to plant death.
Management of Phlox speciosa Pursh ssp. occidentalis Diseases
To manage fungal diseases, it is essential to promote good drainage and air circulation around the plant. Avoid overhead watering and instead water at the base of the plant. If you notice disease symptoms, remove and destroy infected plant debris and avoid composting it. You may also use fungicides to prevent and control the spread of disease.
Common Pests of Phlox speciosa Pursh ssp. occidentalis
The plant can be affected by several pests, including aphids, spider mites, and thrips. These pests often feed on the plant sap, resulting in stunted growth, leaf discoloration, and distortion. Other pests that affect Phlox speciosa Pursh ssp. occidentalis include whiteflies, leafhoppers, and snails.
Management of Phlox speciosa Pursh ssp. occidentalis Pests
To manage pests, it is essential to inspect the plants regularly for any signs of infestation. You may spray the affected plants with insecticides or use neem oil or insecticidal soap. Encouraging natural predators, such as ladybugs, lacewings, and parasitic wasps, can also help control pests. Using sticky traps and removing any potential hiding places for pests, such as weeds or debris, can also prevent infestations.
