Orchid

The Dendrobium genus is one of the largest of all orchid groups with nearly 2,000 species. Native to southeast Asia, these plants grow in all manner of climates—from hot, wet lowlands to high-altitude, cool mountains. Dendrobiums are primarily epiphytes, meaning they grow on other plants. In nature, they’re often found growing on tree branches. While the species vary in appearance, all of them are known for their profuse blooms that come in a variety of pastel tones. Some species bloom all along the lengths of their stems while others bloom just from the tops of the stems.

Dendrobium Orchid Care
Dendrobium is a very large genus with hundreds of species, so it is difficult to generalize care needs since each species will have its own requirements. Generally speaking, though, the dendrobiums require relatively warm conditions, above 60 degrees but no more than 85 degrees Fahrenheit during the growing season. While some types of orchids require pruning in order to prompt reblooming, with dendrobiums, reblooming is likely to be prompted by a winter rest period, where the plant is kept at lower temperatures and water is withheld for three or four weeks. With some species of dendrobiums, only a single rebloom is possible, while other species may rebloom four or five times each year.

Dendrobium orchids make good houseplants and are fairly easy to grow, though they can be picky about their environment. Thus, paying close attention to their growing conditions is key for a healthy, well-blooming plant. In general, these orchids like small pots where their roots can be somewhat cramped, and they need to be by a bright window if you’re keeping them indoors. Plan to water and feed your orchid often during the growing season but then back off in the winter months.

Light
In native settings, these plants grow well in partial sunlight. But indoors they’ll likely need to be by your brightest window—preferably a south-facing window—to bloom well. The appearance of many tiny offshoot plants (known as keikis, pronounced “kay-keys”) on relatively young, small canes can mean the plant isn’t getting enough light. On the other hand, if you see yellow leaves, you might have given the plant too much direct sunlight

Soil
Orchids don’t grow in typical potting soil but rather in a special mixture that mimics their environment in the wild. Use a commercial orchid potting medium, which generally contains peat moss, perlite, or fir bark. Or make your own using those ingredients. Make sure the medium has aeration and is well-draining, so the roots aren’t left in too much moisture for a lengthy period of time

Water
During the growing season, these plants like moisture but shouldn’t sit in a saturated medium. Overwatering can lead to root rot and ultimately cause the plant to yellow or wilt. To determine when you should water, simply stick your finger in the medium. If it feels wet, wait to water until it has dried out slightly. During the winter months, you can put a few more days in between your regular waterings, but don’t let the medium dry out entirely.

Watering with distilled water or collected rainwater is a good idea, as tap water can cause salts and minerals to build up in the pot.

Temperature and Humidity
Dendrobium orchids like warm climates and grow best with daytime temperatures between 70 and 85 degrees Fahrenheit, with a nighttime drop of about 10 degrees. They might be able to withstand slightly cooler nighttime temperatures down to 50 degrees Fahrenheit, but prolonged exposure to cold isn’t ideal. Many types, however, do require a winter rest period where the plant is kept at about 55 degrees for several weeks in order to prompt reblooming.

Dendrobiums prefer a humidity level between 50 and 70 percent (with a minimum of 45 percent). Brown leaf tips can be a sign that the air is too dry for your orchid.2

Fertilizer
Feed regularly during the growing season with a balanced orchid fertilizer, following label instructions. At the end of the growing season, reduce fertilizer by about half.

Pruning
These plants generally send up at least one new upright cane each year. After the flowers fade, they can be clipped off where they join the canes, but don’t cut off old canes, as they store nutrients and water to keep the orchid healthy. Clipping this stem off does not promote reblooming, as it does with some other types of orchids.

Old canes also will sometimes flower or produce tiny offset plants, called keikis (pronounced “kay-keys”), that can be potted on their own after they develop roots.
Propagating Dendrobium Orchids
If your plant has at least four canes bearing healthy leaves, you can divide it. Here’s how:

Use a large stiff knife to cut through the rhizome and root mass, attempting to keep the root mass as intact as possible.
Remove all the growing medium from the root mass, and then cut away any long dangling or dead roots.
Put the plant in a pot close to the size of its root mass, and cover the roots with orchid potting medium.
Press down the potting medium firmly, and wait one week to water it thoroughly.
Another propagation method is to simply prune away the small offset plants (keikis) that sometimes appear at the base of old, mature canes and replant them in their own pots. However, these offsets will take longer to become mature, flowering plants than if you create larger divisions.