To a new owner, keeping an orchid healthy is difficult, as is telling whether it’s healthy or not. But your orchid’s leaves can tell you whether it’s overfed, underwatered, developing an infection, or getting enough sunlight. So what signs should you be looking for?
What do healthy orchid leaves look like? Healthy leaves are green, waxy and shiny, smooth, firm but bendy, and large. Unhealthy orchid leaves are wrinkled and brown, floppy or droopy, and can have black spots, brown spots, or holes depending on the issue affecting them. If a leaf is particularly unhealthy, you can cut it away. Whether you do or not, your orchid should grow new leaves that will hopefully be bigger than the last.
The guide below is a short and sweet one. It details exactly what you can expect from a healthy orchid leaf: the shades of green it will be at various points throughout its life, for example, and what it’s supposed to feel like when you pinch or bend it.
What Do Healthy Orchid Leaves Look Like?
If you’ve owned orchids for a while, it becomes very easy to identify healthy leaves from unhealthy ones.
At the risk of being obvious, a healthy orchid leaf should be green!
Orchid leaves go through several stages of greenness. They start life as a rich, grassy green color. A new orchid leaf will be this rich green towards its tip, and a lighter green towards the crown, which is where it emerges. This light green gradually matures over time. Older orchid leaves should still be green, but perhaps not quite as vibrant and rich in color. They’re a deep, dark green instead.
It’s often a sign of ill health for an orchid leaf to be a color other than green. Brown patches, for example, can signify rot. Yellowness or brownness across the whole leaf indicate that the leaf is nearing the end of its useful life. Black and white patches can indicate sun damage, and small black spots are a sign of fungal infection.
Healthy orchid leaves should also be waxy and shiny.
This is something that I associate with new leaves. If truth be told, I’m quite lazy about cleaning my orchid’s leaves. Over time, dirt, dust and water stains build up on the leaf and take away its natural lustre. Only newer leaves, that haven’t had time to get dirty in the same way, are still shiny.
The waxy coating on leaves is called the cuticle. It’s made of a substance called cutin, which is like wax, and is chemically speaking a kind of fatty acid. The point of a waxy coating is that the leaf doesn’t lose water as easily. This stops it from drying out. Many bugs have a similar coating on their shells for the same reason. Leaves look less waxy over time because dust, dirt and grime cover the surface to make it less smooth. The less smooth the surface, the less light it reflects.
I really should start cleaning my orchid’s leaves more…
Smooth (Not Wrinkly)
A healthy orchid’s leaves should be smooth, not wrinkled.
This is a function of how much water the leaf is getting. Orchids lose water gradually through respiration, just like we do. If that water isn’t replaced, the leaf loses mass, as water is what plants are mostly made of. Like our skin, when it loses moisture and mass, it becomes wrinkled and dried. If you water your orchid correctly, much of this wrinkling can be reversed, but not all.
By contrast, a healthy leaf is smooth from tip to crown. You may notice some microscopic lumps and bumps in the surface of the leaf, but these are normal, and are related to the internal structure of the leaf. You can feel this smoothness if you run your finger over the leaf. The same applies to the underside of the leaf, which should also be smooth. Besides wrinkling, issues like infections, dust and dirt can all change the texture of your orchid’s leaf.
This smoothness adds to the shiny effect described above. The smoother it is, the shinier it will be.
Firm But Pliable
Your orchid’s leaf should be firm and hold its shape. It should move back to that shape if bent and let go.
As is often the case, this is related to the water content of the leaf. The water content fills out the leaf’s internal structure, almost like a water balloon that’s filled with water. At the same time, the leaf is organic, so it will have an obvious organic feel to it.
By contrast, an unhealthy leaf will be floppy and limp. The leaves will droop down over the sides of the pot, and if you lift them up, they will flop back down again. This happens when the leaf doesn’t get enough water, just like how wilted flowers lose their shape.
The leaf may also be wrinkled, as described above. If it’s dead, then it will ironically become dried rather than floppy; it will be hard but not pliable and bendy like a healthy leaf.
Long, Thick & Wide
An orchid that’s in good health will grow leaves bigger than its last pair. An orchid that could be healthier will grow leaves that are smaller.
This is something that I see a lot. One of my orchids, which I talk about a lot, had a fungal infection a while back. We managed to stave the infection off by using an anti-fungal spray, but she was in bad health generally: some of her leaves were badly infected and had died, her crown had become infected, new roots she’d tried to grow had been infected… When she grew new leaves after the infection had passed, they were smaller than the previous pair.
But we’ve also got lots of orchids that are growing larger. One is a tiny basal keiki which we cut away and grew separately. Her newest leaf is maybe twice the size of her last one, and hopefully the next one will be twice as big again!
The reason why new leaves on an orchid are bigger if it’s healthy are simple. Orchids create sugar from photosynthesis. If the orchid’s old leaves are healthy and clean, they can take in more light through photosynthesis and make more energy. If the orchid’s roots are healthy, and it’s watered often, then it can use that water to grow new tissue. But if its roots or leaves are unhealthy, it can’t get as much energy or water, and so can’t grow as much tissue.
As well as being long and wide, your orchid’s leaves will hopefully be thick. The thickness of the leaf is another function of its structure. The bigger and healthier the leaf, the more tissue will have been put into making it, so the thicker it will be.
Straight Or At An Angle
It may look better for an orchid’s stem to stand straight up, and for its leaves to be perfectly horizontal, but that’s not necessarily a sign of good health.
As orchids grow older, they grow more and more leaves. These replace the leaves at the bottom of the orchid’s body. Ideally, you want them to be bigger than the leaves that came before. But if you’re like me, you also want them to stand up straight. If they do, you won’t have to repot your orchid as often.
But just because something is convenient for me, doesn’t mean it’s healthy for an orchid. There’s nothing unhealthy about leaves growing out at an angle, and a perfectly straight orchid might be unhealthy in other ways. Most of my orchids have developed a lean in one direction or another. Some I try to correct slightly by using stakes, which I loosely tie their stems to. Others I repot so that they stand a little straighter. But you don’t strictly need to do this, as there’s nothing about growing at an angle that’s unhealthy. In fact, this is what wild orchids often do—particularly those that grow on trees.
To spot each of these signs, I can’t recommend anything more than spending a little time on yourself and your orchids. It’s almost a cliche these days to say that we need to be more mindful, practise self-care and relax… But it’s true! Spend time checking on your orchids to see if they look healthy or unhealthy, and adjust how you care for them in response.