I Was Today Years Old When I Learned About Deciduous Orchids

Dendrobium nobile, a popular deciduous orchid. Photo credit: CT Johansson via Wikimedia

Think back to elementary school science class or whenever you learned the basics about Earth. Remember the three types of rock (sedimentary, igneous, and metamorphic)? The five classes of vertebrates (fish, amphibians, reptiles, mammals, and birds)? What about the two main types of trees: deciduous and coniferous? I struggled to keep those two straight back then, and I still have to remind myself that coniferous trees have cones, like evergreens, and those are the ones that keep their leaves or needles year-round. Deciduous trees lose their leaves every year, and here in New England, they put on quite a show before they do. 

What I didn’t know until recently is that a number of trees species are actually both. The larch tree, for example, has needles that turn yellow in autumn and then fall off. Known as a “deciduous conifer,” such species defy the simple binary categorizations we learned in elementary school.

Dendrobium nobile (Photo credit: Stefano via Flickr, CC 3.0)

If there’s any plant out there that transcends labels and expectations, it’s the orchid. I just learned that there’s such a thing as a “deciduous orchid,” though I suppose I shouldn’t be surprised. 

Many of the 17,000 wild dendrobium orchid species, though not the kind I have, are deciduous. Like maple and oak trees, they lose their leaves in the winter and go through a dormant period. During the resting phase, a deciduous orchid doesn’t want much water (just enough to keep the pseudobulbs from shriveling), heat, or fertilizer, but unlike conventional bulbs and many other plants that go dormant in the winter, a deciduous orchid still wants bright light. Deciduous dendrobiums will flower—especially with lower nighttime temperatures over the winter—before starting to grow again in the spring. 

Lycaste aromatic, a deciduous type (Photo credit: sunoochi via Wikimedia)

Almost all types of catasetinae orchids are deciduous as well. These usually flower before dropping their leaves each year. Some lycaste species are deciduous as well.

Many orchids, including the other lycastes, are “semi-deciduous,” which means that they don’t shed leaves regularly every fall, but they do lose older leaves from their pseudobulbs. Orchids such as cattleyas have pseudobulbs, which help store nutrients and promote growth. I’ve been wondering recently if my cattleya orchid is doing okay because I’ve noticed bald or leafless pseudobulbs. The bulbs aren’t dead or shriveled, but they don’t seem to be doing much. I’m glad to learn that this is normal for a semi-deciduous orchid, and just yesterday I spied a flower spike on my cattleya, so it must not be too unhappy. 

No matter how much I learn about orchids, their weird variations and tendencies will never cease to amaze me. 

Lycaste aromatic (Photo credit: Stefano via Flickr, CC 3.0)