How Much Light Do Orchids Need?
Orchids get a reputation for being fussy, particularly about the conditions in which they’re grown. New orchid gardeners may bring home a species deemed an “easy orchid” only to find they have issues giving them what they need. That’s because light, soil, and watering routines are different for them than for other houseplants.
Knowing how orchids are grown and cultivated, especially in their indigenous settings, is one way to determine how to give them what they need. Understanding how much light to give them is one part of the care regimen that is easy to grasp.
Of course, each orchid has different needs, but we can give most a baseline of settings and environments to help them live. Knowing the particulars allows us to provide them with the conditions they need to flourish and reproduce – even without the assistance of pollinators.
Light and Orchids
Generally, orchids need at least six hours of light per day to live. This goes for indoor orchids, outdoor orchids, and even those in a liminal indoor-outdoor space, like a greenhouse. Some may do best with slightly more, while others do best with a little less.
However, the setting in which the orchids are cultivated is always an indication of the plant’s needs in terms of its ability to remain hardy in the elements. If you’re growing terrestrial orchids used to the prairie’s open light, mimicking those conditions will get you the best results.
More tropical orchids may appreciate the cover of a large canopy of trees, but some may live high in trees where direct sunlight can be accessed for part of the day. Doing some research about the type of orchid you have gives you lots of insight, and so will discussions with expert growers.
Signs of Light Stress in Orchids
As you grow your orchid at home, look for signs of distress. Too much light is easy to spot. In this case, a dark or yellowed area appears and may become white and papery over time. If the issue isn’t remedied, whole leaves may take on a crispy and brittle structure as they dry up.
Like other plants, orchids that have a deficiency of UV rays get spindly and etiolate as they reach to access nearby light sources. The foliage may lack the bright green tinge it gets when the plant is doing well and will take on a dark green color instead.
Orchids that don’t have enough light will bloom less frequently as well. Monitor these symptoms and adjust as needed to keep your orchid in the best possible circumstances.
How Much Light Do Orchids Really Need?
While we’ve established that light needs depend on the kind of orchid, we’ve also identified a baseline: at least six hours of light. Whether or not that light is direct, indirect, or slightly obstructed depends on the orchid in question.
Let’s examine some orchids categorized by habit and discuss their general light needs. Those who receive more direct sunlight in their natural ecosystem may even do well with eight hours of light per day, so there are particulars to consider.
Terrestrial Orchids
Ground orchids are some of the most sun-tolerant types across the board. In fact, most North American orchids are terrestrial, growing in the soils of prairies, woodlands, bogs, and even deserts. Where they tend to grow in the wild will tell you all you need to know about the light they need.
Prairie and desert orchids, like Lady’s Tresses and the Chiuauan Desert orchid (respectively), can handle direct sunlight for up to eight hours a day. Terrestrial species are, therefore, great for outdoor settings without a ton of shade.
If you have an orchid that likes the shadier swampy areas of Florida, like the Butterfly orchid, provide a little shade or dappled sunlight for six to eight hours per day. Cranefly orchids that prefer the forest floor can take partial shade that whole time.
No matter where your orchid originates – as there are many terrestrial species worldwide – refer to the care instructions the environment and growers give you. You’ll have lovely thriving orchids this way.
Epiphytic Orchids
Epiphytes attach themselves to trees and gather nutrients and light from the area around them. Because they grow on trees, they’re typically shaded from direct UV rays and prefer offset or indirect lighting.
Take the ever-popular epiphytic Venus slipper, for instance. This type has multiple species associated with its name. All hail from Southeast Asia, India, southern China, New Guinea, and around the Solomon Islands. These tree-dwellers grow in tropical rainforests and marshes.
Their light tolerance is much lower than that of a prairie or desert orchid, and you should consider this when placing yours in its growing area. Plant yours in a hanging basket or mount it and suspend it from the shaded areas of your outdoor garden or greenhouse.
Those indoors should receive six to eight hours of bright, indirect light. Again, modify this if you’ve got another kind of orchid that prefers slightly more light, especially if it rests naturally in higher elevations where tree leaves don’t shade the sun.
Lithophytic Orchids
Unlike the other two types of orchids we’ve discussed up to this point, lithophytes prefer rocks. They use their aerial roots to climb and affix themselves to rocky areas in low and high elevations. Many moth orchids and Dendrobium orchids thrive in rocky grit.
But these rocky areas aren’t always fully exposed to bright light. Some are in mountainous woods, and some may be on shaded cliff faces. They may develop significant, sparse roots for clinging or send out dense mats of roots. Either way, knowing where they were sourced is instructive.
For example, take Vanda hybrids: you’ll want to mimic their rocky habitat on heavily shaded forest floors. Give them just a bit of dappled light each day. On the flip side, the rat tail orchid prefers lots of bright light in the open rock faces it thrives on.
Providing Light to Orchids
Now that we’ve touched on the basis of your lighting for orchids, let’s discuss a few tips to help you in your orchid-growing adventure. The best possible scenario for a new grower is adaptable and adjustable. This gives you a period where you can make changes to give your orchid the highest chance of thriving.
Plant Outdoor Orchids In Containers
If you’re interested in growing terrestrial orchids, that’s great! When you grow an orchid that prefers soil or more compacted media than the usual bark, that substrate will naturally hold more heat. This makes the orchid more resilient to changes in light and temperature.
But before planting in the ground, try cultivating them in pots first. As they grow, move them around as needed and identify the best locations throughout the year. Then, plant them in the ground when you’ve found the optimal space.
If you grow in containers, you have lots of room to change your positioning. If you find an orchid advertised for growing outdoors that turns out more sensitive, this gives you the chance to grow indoors instead.
Of course, the same principle applies to mounted orchids. Move them around when necessary to figure out their perfect spots.
Use Natural Light
Indoor and outdoor orchids will do fine with offset sunlight, especially if they prefer a bright, indirect light source. A west-facing or south-facing window in the northern hemisphere (opposite for southern hemisphere dwellers) is often a perfect light source, as long as you set your plant just to the side.
If you have a window with many obstructions, this is not the best option. Moving closer to the window can help. A shady window is ideal for many common orchids with their substantial aerial roots.
Supplement With Grow Lights
Of course, if you find the light inside your house or greenhouse insufficient, you can always provide additional light with a grow light. You want to use a cool white tube or a broad spectrum tube to light your orchid. The lights you’d use to sprout your veggie crops are too bright.
The American Orchid Society has a great guide about providing indoor or supplemental lighting via fluorescent bulbs. Consult this if you know you’ll need to use grow lights or find it hard to provide natural light to your plants.
Final Thoughts
While orchids sometimes get a bad rap for being picky about their growing conditions, you can be sure yours will do just fine if you consider where they came from. Provide them with the light they need, and you may find them much easier to grow than you expected!
Most of all, know that your conditions can change and adapt to the plant’s needs. A few small adjustments can make all the difference.