Cool-Growing Orchids: Varieties, Care Tips, and Recommendations

Cool-growing orchids are a rewarding group of plants for growers who can maintain lower temperatures and high humidity. These orchids, native to cloud forests and cooler regions, require specific care to thrive.

Cool-growing orchids are a favorite for enthusiasts who enjoy a bit of a chill in the air. These orchids, thriving in temperatures ranging from 50–70°F, include stunning varieties like Masdevallias, Odontoglossums, Cymbidiums, and Paphiopedilums. Known for their unique forms and vibrant blooms, these plants bring diversity to any collection.

Types of Cool-Growing Orchids:

1. Masdevallias: Compact orchids with striking triangular flowers, perfect for terrariums.
2. Odontoglossums: Featuring intricate patterns and rich colors, they add elegance to any orchid setup.
3. Cymbidiums: Known for long flower spikes, they bloom during fall and winter.
4. Paphiopedilums: With their slipper-shaped flowers, these orchids offer exotic beauty.

1. Light Requirements

Cool-growing orchids prefer bright, indirect light. Direct sunlight can scorch their leaves, so east-facing windows or shaded greenhouses are ideal. Masdevallias and Odontoglossums, for example, thrive in low to medium light, while Cymbidiums and some Paphiopedilums need brighter conditions.

Tip: Use sheer curtains to filter sunlight or grow lights if natural light is insufficient.

2. Temperature

These orchids thrive in temperatures ranging from 50–70°F (10–21°C). Many benefit from a noticeable temperature drop at night to encourage blooming. For example:

• Masdevallias: Prefer consistent cool temperatures.
• Cymbidiums: Require cooler nights, especially during the fall, to trigger flowering.

Tip: Place plants outdoors in cooler weather (but avoid frost) to mimic their natural environment.

3. Watering

Cool-growing orchids prefer consistent moisture but need well-draining media to avoid waterlogged roots. Water frequency depends on the season:

• Water more frequently during active growth.
• Reduce watering during dormancy or cooler months.

Tip: Use rainwater or distilled water, as many cool-growing orchids are sensitive to hard water and salts.

4. Humidity

Humidity levels of 50–70% are critical. In dry climates, increase humidity by:

• Using a humidifier.
• Placing orchids on a humidity tray filled with pebbles and water.
• Grouping plants together to create a microclimate.

Tip: Ensure good airflow to prevent fungal infections.

5. Potting Media and Repotting

Cool-growers need an open, airy medium like bark, sphagnum moss, or a mix of both. Repot every 1–2 years or when the medium begins to break down.

• Masdevallias: Do well in sphagnum moss for added moisture retention.
• Cymbidiums: Benefit from a mix of bark, perlite, and charcoal.

Tip: Repot after blooming to minimize stress.

6. Fertilizing

Use a balanced orchid fertilizer (20-20-20 or similar) diluted to half strength. Feed every two weeks during the growing season and reduce feeding during dormancy.

• For Cymbidiums: Switch to a bloom-boosting fertilizer (high in phosphorus and potassium) as spikes form.

Tip: Flush the medium monthly with plain water to remove salt buildup.

7. Pests and Diseases

Watch for pests like mealybugs, spider mites, and aphids. Treat infestations early with insecticidal soap or neem oil. Prevent fungal issues by:

• Avoiding overhead watering.
• Ensuring good airflow.

Tip: Regularly clean leaves and remove dead material from pots.

8. Blooming and Dormancy

Some cool-growers, like Cymbidiums, require a seasonal dormancy period with reduced watering and feeding. Others, like Masdevallias, bloom continuously with proper care.

Tip: Mimic seasonal changes in light and temperature to encourage blooms.

Cool-growing orchids, while requiring specific conditions, reward growers with exquisite blooms and unique foliage. For plants and  supplies, visit Waldor Orchids and Orchid Nerd.