Platanthera chorisiana (Cham.) Reichenb.
Platanthera chorisiana is an orchid species that is native to northern and central parts of North America, including Alaska, Greenland, Canada, and the United States. The plant has several common names including Choris' Orchid, Choris' Platanthera, and Alaska bog orchid.
Appearance
The plant produces a basal rosette of leaves that are dark green, oblong, and slightly glossy. Each stem of Platanthera chorisiana produces a single spike of fragrant white flowers during the summer months. The flowers of Platanthera chorisiana are small, tubular, and arranged in densely packed clusters that grow up to 20 cm in length. The plant can grow up to 60 cm tall and can spread out to 30 cm wide.
Uses
Platanthera chorisiana is a popular ornamental plant that is cultivated for landscaping purposes. It is also used in traditional medicine in some indigenous communities in Alaska and Canada. The plant has been known to have analgesic, anesthetic, and anti-inflammatory properties. However, Platanthera chorisiana is not widely used for medicinal purposes as it is not very abundant in the wild and is a threatened species in some regions.
Light Requirements
Platanthera chorisiana requires a bright location, with indirect sunlight. This orchid prefers a partially shaded location where it can receive diffused or filtered light. Direct sunlight can cause sunburn on its foliage and affect its growth and survival.
Temperature Requirements
The ideal temperature range for Platanthera chorisiana growth is between 60°F to 80°F (15.5°C to 26.6°C). This orchid is cold tolerant and can withstand cooler temperatures, but it also requires warmth to grow well. Avoid exposing this orchid to extreme temperature changes that can affect its growth and development.
Soil Requirements
This orchid prefers sandy, humus rich soil that is well-draining and aerated. It prefers a slightly acidic to neutral soil pH level between 6.0 and 7.5. The soil should not be allowed to dry out completely, but the plant should not be sitting in water, as this can cause root rot. Adequate drainage is essential to ensure the healthy growth of the Platanthera chorisiana.
Cultivation
Platanthera chorisiana is a terrestrial orchid that grows well in humus-rich soil with good drainage. It requires bright light but not direct sunlight and prefers a moist but not waterlogged environment. It can be grown in a pot or in the ground in a garden bed and is best suited for USDA zones 4-9.
Watering Needs
Platanthera chorisiana requires regular watering to maintain the soil moisture level. It is crucial not to let the soil dry out completely, which can cause the plant to wither and die. The most effective method of watering is to soak the soil, and then allow it to drain thoroughly. Once the top layer of soil feels slightly dry, it's time to water it again.
Fertilization
Platanthera chorisiana does not require frequent fertilizer applications, but a slow-release fertilizer specifically formulated for orchids can be applied once a month during the growing season. The recommended nitrogen, phosphorus, and potassium ratio for the fertilizer is 20:10:20. Over-fertilizing can lead to burn or damage to the plant's roots.
Pruning
Platanthera chorisiana does not require regular pruning, but yellowing or dead leaves and stems should be trimmed to maintain the plant's appearance and promote new growth. The pruning should be done with sterile pruning shears or scissors to avoid transmitting diseases or infections from one plant to another. Any damaged or diseased parts of the plant should be removed immediately.
Propagation of Platanthera chorisiana
Platanthera chorisiana, also known as Chamisso's Orchid, can be propagated through several methods:
Division
The most common method of propagating Platanthera chorisiana is through division. This is best done in the spring when new growth appears. Gently dig up the entire plant and carefully separate the rhizomes into smaller sections, with at least one healthy shoot and root system. Replant the divisions in well-draining soil and keep them moist until they become established.
Seed Germination
Another method of propagating Platanthera chorisiana is through seed germination. Collect the seed pods when they turn brown and begin to split open. Collect the seeds from the pods and sow them immediately in a well-draining, moist soil mix. Cover the seeds lightly with soil, mist them with water, and cover the pot with clear plastic or glass. Place the pot in a warm, bright location, but avoid direct sunlight. Keep the soil moist and watch for germination in a few weeks.
Tissue Culture
Platanthera chorisiana can also be propagated through tissue culture. This involves taking a small piece of the plant and growing it in a sterile container with a nutrient-rich medium. This method is more complex and best left to experienced growers or professionals.
Disease and Pest Management for Platanthera chorisiana (Cham.) Reichenb.
Platanthera chorisiana is a beautiful orchid that can be grown in various environmental conditions. However, like any other plant, it can fall prey to pests and diseases. Hence, it is essential to implement effective disease and pest management strategies to keep the plant healthy and thriving.
Common Diseases
Platanthera chorisiana is susceptible to a few diseases, including root and stem rots, virus infections, and fungal diseases. Root rot is a common problem caused by soil-borne pathogens. Symptoms include yellowing of leaves, wilting, and stunted growth. Stem rot can be identified by blackening and softening at the base of the stem.
Virus infections can result in ring-shaped spots on leaves, stunted growth, and distorted flowers. Fungal diseases like anthracnose, leaf spot, and powdery mildew can cause leaf yellowing and defoliation. To manage these diseases, it is essential to maintain proper cultural practices such as watering, fertilization, and pruning to reduce stress on the plant. It is also important to avoid overwatering and maintain good drainage to prevent root rot. In severe cases, fungicides may be required, but consulting with a professional is recommended.
Common Pests
Platanthera chorisiana is also vulnerable to a variety of pests, including thrips, spider mites, snails, slugs, and aphids. Thrips are tiny insects that cause leaf damage, causing the leaves to look silvery and distorted.
Spider mites are mites that feed on the plant's cell content, causing stippling and yellowing on the upper leaf surface. Snails and slugs eat holes through the leaves while aphids suck sap from tender plant parts and cause leaf distortion. Insecticidal soaps, neem oil, and diatomaceous earth can be used to control these pests. However, it is important to use these products as directed, and avoid excessive use to prevent harming the plant.
Implementing good cultural practices such as maintaining cleanliness, proper irrigation, and using disease and pest-free planting material can significantly reduce the occurrence of diseases and pests in Platanthera chorisiana.
