Lady Slipper Orchids (Cypripedium): A Comprehensive Guide to Cultivation and Care
Lady Slipper Orchid Characteristics
Lady slipper orchids, belonging to the genus Cypripedium, are captivating plants known for their unique pouch-shaped flowers. They are the most primitive orchids found today, with most species growing terrestrially in temperate regions around the world. Lady slipper orchids are characterized by their slipper-like lip, resembling the toe of a shoe.
Types of Lady Slipper Orchids
Numerous species of lady slipper orchids exist, each with its own distinct characteristics:
- Pink lady slipper (Cypripedium acaule): Produces deep pink flowers in late June to July.
- Yellow lady slipper (Cypripedium calceolus): Features a buttery yellow flower that blooms in early spring.
- Greater yellow lady slipper (Cypripedium parviflorum pubescens): Can reach up to 2 feet tall, with flower petals up to 6 inches across.
- Showy lady’s slipper (Cypripedium reginae): A large species with pink-streaked, white flowers that bloom in late spring or early summer.
- White lady’s slipper (Cypripedium candidum): A small type that is considered endangered.
Lady Slipper Orchid Care
Lady slipper orchids require specific care to thrive:
Light: They prefer low, indirect light conditions. East-facing or shaded south-facing windows are ideal. Fluorescent lighting is also suitable.
Soil: Most lady slipper orchids are terrestrial and grow in specific soil types. Suitable potting materials include shredded osmunda bark, medium-grade fir bark, and crushed dried oak leaves. Avoid packing the mix too tightly.
Water: Like other sympodial orchids, lady slipper orchids store water and nutrients in their pseudobulbs, allowing them to go a while between waterings. Water when the potting medium feels slightly dry to the touch. Avoid overwatering.
Temperature: Different species of lady slipper orchids have specific temperature requirements. Mottled leaf types thrive in daytime temperatures between 75 and 85 degrees Fahrenheit and nighttime temperatures from 60 to 65 degrees Fahrenheit. Green leaf types prefer daytime temperatures between 75 and 80 degrees Fahrenheit and nighttime temperatures between 50 and 60 degrees Fahrenheit.
Humidity: Moderate humidity of 40 to 50 percent is adequate. Place the orchid pot on a tray of gravel partially filled with water to maintain humidity. Avoid letting moisture sit on the leaves or crown of the plant.
Fertilizer: Lady slipper orchids are sensitive to fertilizer. Use a balanced orchid fertilizer diluted to 1/4 to 1/2 strength and apply once every two weeks during the growing season. Flush with clear water once monthly to remove harmful salts.
Lady Slipper Orchid Propagation
Propagating lady slipper orchids can be challenging, but it is possible through several methods:
Keikis:
- Keikis are baby plants that form on the stems of mature lady slipper orchids.
- To propagate via keikis, mound up potting medium around the baby stem to create a pot within the original orchid pot.
- Wait for the keiki to develop roots, then cut it from the mother plant and plant it in its own small pot.
Lady Slipper Orchid Repotting
Repotting lady slipper orchids is necessary when they become pot-bound or the potting medium becomes depleted:
- Choose a pot with good drainage holes that is slightly larger than the root ball.
- Use fresh potting mix and gently remove the orchid from its old pot.
- Inspect the roots and remove any damaged or diseased ones.
- Place the orchid in the new pot and backfill with potting medium.
- Water thoroughly and let the orchid rest for a few days before resuming regular care.
Common Pests and Diseases of Lady Slipper Orchids
Lady slipper orchids are susceptible to a few common pests and diseases:
Pests:
- Mealybugs: Small, white, cottony insects that can be removed with a q-tip dipped in isopropyl alcohol.
Diseases:
- Botrytis petal blight: Causes small dark spots or patches on flowers. Remove affected parts and improve air circulation.
Lady Slipper Orchid Blooming
Lady slipper orchids can produce flowers for up to three months annually. Most species produce one or two flowers, but some hybrids can produce many. To encourage blooming:
- Use a fertilizer slightly higher in phosphorus as the bloom period approaches.
- Keep the orchid in total darkness at night.
Common Problems with Lady Slipper Orchids
Improper care can lead to various problems with lady slipper orchids:
- Yellowing leaves with black spots: Caused by exposure to cold or wide temperature fluctuations.
- Dry or dark leaf tips or edges: May be sunburn. Ensure the orchid receives only dappled, indirect light.
- Stunted growth or sudden flower loss: Can be caused by using cold water. Always use lukewarm or room temperature water when watering.
Frequently Asked Questions
Q: Are lady slipper orchids difficult to grow? A: Yes, lady slipper orchids can be challenging to grow, especially for beginners. They require specific environmental conditions and specialized care.
Q: Can I dig up a lady slipper orchid growing on my property? A: Check with your state’s endangered plant list before digging up a lady slipper orchid on your property. Never wild harvest a single plant; instead, take only what you need from a colony.