Possibly the fastest growing orchid, this terrestrial replaces these tall stalks each year. New leaves emerge from the base of the previous year’s stalk (actually a pseudobulb,) and the new growth shoots up in just a few months. This species is native to the slopes of the Himalayas, and has a wide range from India east to Vietnam and north to China.

When new spring growth emerges after winter dormancy, Thunias need light watering and full sun. Too much water can rot new growth. Within a few weeks, the new stalks grow 6 inches (15 cm,) and should be moved into shadier conditions. By late spring, Thunias need heavy water and fertilizer to mimic the Indian Ocean monsoon in their native homes. After blooms that last a couple weeks, leaves turn yellow in the early autumn. At this point, watering and fertilizing should be reduced to a minimum. I keep this specimen cool and dry in winter, watering as seldom as once a month to keep the stalks from shriveling too much. If these varying seasonal care needs seem too daunting, just imagine the reward of seeing these gorgeous flowers hanging off a cornstalk.

Also known as the False Ladyslipper, the Stream Orchid is not an air plant. It’s a terrestrial orchid that lives in moist soils along streams, on cliff faces, and in mountain bogs. The plant dies back during winter, and re-emerges from underground tubers the next spring.

Many terrestrial orchids are difficult to grow, requiring highly specialized conditions (yet another reason why you should NEVER remove wild orchids from their natural homes.) However, Epipactis gigantea is relatively easy to cultivate, and adapts to a wide range of conditions. I keep mine in regular potting soil, and keep the pot in a tray of water so it never dries out. It loves a good dose of compost fertilizer, which has helped my plant grow into a vigorous specimen. Certainly it seems right at home.

• Move orchids from their brighter winter locales to the shade needed for spring and summer. For most orchids, if leaves are a light green color, then the orchid is receiving enough light to bloom.
• Keep an eye out for new leaf and root growth, which often starts after flowers finish. This is a good time to repot, if necessary.
• For dormant orchids, increase watering and fertilizing gradually. With deciduous orchids like Bletilla and Cycnoches, water new growth sparingly for the first few weeks. Too much water can rot new leaves.
• As always, maintain high humidity and good air movement around plants. New growth is especially susceptible to pests when the air is dry or stagnant.
• For growers in colder climates, continue to watch for pests, keep plants in brighter light, and take heart that the long winter shall pass.

This species is native to a large area from Mexico south to Colombia, Venezuela and east to Jamaica. Each 4 – 5 inch (10 – 13 cm) spike has dozens of small flowers neatly arranged in a spiral pattern. The last shot in this set shows unopened buds, a reminder that flowers can have charms even before they bloom.

This Hyacinth Orchid supports dozens of flowers even though it’s in its dormant season. I just let our sporadic winter rains take care of it, and don’t add water or fertilizer. With heavier rains, I move it below deck to keep it on the drier side.

• Cattleya
• Cymbidium
• Dendrobium
• Epidendrum
• Miltonia
• Odontoglossum
• Oncidium
• Vanda

The following orchid varieties do not experience a dry season, but with lower light levels and cooler temperatures, it’s ok to give them a little less water also.

• Masdevallia
• Paphiopedilum
• Phalaenopsis

It’s always worth repeating that orchids need good humidity, but the dry air of home and office heating provides an extra challenge. Low humidity can cause blooms to wilt quickly. Dry air also invites pests, especially spider mites and scale.

Finally, consider adding extra light to compensate for the weak winter sun. That should keep you busy, but remember that repotting season is just around the corner.

The flowers look like Cattleyas, but the similarities end there. Unlike Cattleyas, this Sobralia species likes heavy water and fertilizer, and doesn’t mind cool temperatures. Native to rainforests from Mexico to Costa Rica, it grows in a wide variety of conditions. It lives at elevations as high as 11,000 feet (3400 m.) That helps explain why it can tolerate a wide range of temperatures. Mine lives outdoors on the deck all year, and I try to keep it on the dry side for its winter dormancy.

Sobralias like to be potted in small pots and dislike repotting. Their bamboo-like leaves grow on strong stems. Although this species can grow up to 7 feet (2.1 m) tall, my plant is only 1.5 feet (0.5 m.) The contrast of such a large flower on a short plant provides a striking effect.

No matter what they look like, pseudobulbs serve the same purpose: to provide a reserve of water and nutrients for the orchid. Some varieties can survive for months during a dry season in their native homes. To mimic this natural dormancy, growers can cut back on watering during fall and winter. Wait and watch for the pseudobulbs to shrivel slightly, and then water. Depending on other factors, such as light, temperature, humidity, and air movement, dormant orchids may only need water once or twice a month during winter.

Unlike tulip bulbs, orchid pseudobulbs need to be kept completely above the potting material. They’ll rot underneath bark or moss. The final picture shows a Cattleya with papery sheaths that are typical for some varieties. The sheaths start out green, but eventually dry and fall off.

Orchid varieties without these storage devices, such as Phals, Paphs, and Masdevallias, do not go truly dormant. However, with less light and cooler temperatures in winter, growers can cut back watering slightly. Maintain high humidity for all orchids during winter, whether they have pseudobulbs or not.

This Stenoglottis is not an air plant like most commonly cultivated orchids. Instead it’s a terrestrial, and can grow in regular potting soil. In its native South African home, it also grows on rocks and rotting logs. Its blooms remain even as its leaves drop before going dormant in winter. I’ve already curtailed watering, and I’ll let it stay dry for its next few months. Eventually the final blooms will fade as well. In spring, new leaves will start to grow from the fleshy roots, and I’ll increase watering and fertilizing.

If the sun isn’t cooperative, you may want to add artificial lights to boost light levels for the dormant season. Fluorescent lights work well since they last a long time, use little electricity, and don’t get very hot. Light bulbs should be close to the leaves, just 6-8 inches (15-20 cm) away, but not so close that leaves can burn. Just like natural light, any increases with artificial light need to be done gradually. Burns can cause large dead spots on leaves, usually starting white and then turning black. If leaves turn reddish at the edges, then the orchid is receiving its maximum light exposure. That’s good because it’s a guarantee the orchid is getting enough light to bloom, but stay vigilant to prevent burns.

Remember that most orchids need enough light to keep their leaves a light green color. Dark green leaves may mean insufficient light, while yellow leaves may mean too much light. Most importantly, when spring arrives don’t forget to move orchids back into the shade.

If you fertilize with a high nitrogen fertilizer, like 30-10-10, its time to switch to a low nitrogen variety, such as 10-30-30. No matter what kind of fertilizer you use, start to taper off with weaker solution and less frequent doses. Many orchids are beginning to enter a dormant stage. Start to reduce watering for Cattleyas, Cymbidiums, Dendrobiums, Epidendrums, Miltonias, Odontoglossums, Oncidiums, and Vandas. This mimics the start of the dry season in their jungle homes, and it’s part of the annual cycle they need to bloom. Maintain good humidity as always, and compensate for the dry air of home and office heating.

If a few lower leaves yellow or drop, don’t panic. Some Dendrobium varieties completely shed their leaves, but they’re just dormant, not dead. Continue to give them good light and humidity, and they’ll spring back to life in a few months.

If your Phals aren’t blooming right now, give them a few weeks of cooler nighttime temperatures. This can cause them to start growing a flower spike. Then you’ll really have some fall color to enjoy.