I noticed this post has been getting a lot of traction in the fall, then I read through the issues and I also realized that the most common question people were asking online was not answered. That question—”what are these spots on my orchid?” I’ll will address this problem first, but if you read on further, this article is also about water and light related issues.
Discolored Spots, Damage, or Pits on a Phalaenopsis Leaf
Phals are tropical plants so they are used to operating in a relatively narrow range of temperatures. Leaf damage can come from 3 main things: cold damage, heat damage (often not from too much light, but from the heat caused by too much light), and virus-related damage.
Heat damage is the easiest to identify – it happens during high temps or from direct sun, and if it’s the latter the symptom is a giant white (or black) spot of dead tissue. Heat damage is irreversible. If your phal gets heat damage, hopefully it’s not bad enough to kill the plant, and it only affects a section of the leaf or top leaves. If you start to see yellow stippling on the surface of your phal’s leaf and it’s growing near a bright window where sun is in contact with the leaf – move it. All it takes is a hot day, or a very bright day to scorch the leaf.
People are warned not to water in the evening specifically because of cold-related damage, but Phals don’t need to be wet to suffer from cold damage. Keep them away from open windows in the fall, and avoid letting your phal temps going under 16C (be mindful of open windows). You might be okay with temps down to 13-14C briefly during shipping, but don’t grow them this cold.
A phal can experience two types of cold damage:
- Fungal Infection – this is more of an educated guess than proven fact, but I’ve heard it discussed multiple times. It’s believed that many phals have or carry a Taiwan form of micro fungus (whatever the hell that is) and when the temperatures go too low, the fungus is able to overtake or damage the plant. This results in yellow spots, or necrotic tissue. It also looks similar to viral damage, but I haven’t managed to find clarity on the details. The takeaway is this: cool temps can result in yellow or black spots on your phal – and the spots begin within the leaf and can spread quickly. If you’re seeing this problem get your plant to a warmer place, isolate it away from other plants (as it’s reported to spread quickly across a collection) and if possible use a systemic fungicide such as Phyton27. Also, be sure to keep your phalaenopsis away from open windows…if it’s fall or winter and you have a window open a crack, a sub-zero night can create drafts across your plant, quickly killing the tissue – THAT type of damage looks a bit different;
*For more information about this micro fungus, click here or here.
- Mesophyll Cell Collapse caused by cold air or cold water on the leaves. The condition is quite common in the fall as temperatures drop, especially in the evenings – but symptoms of damage may not be visible for weeks after the drop in temperature happened. The American Orchid Society has a detailed page on the topic, so go there and read their info. The takeaway is this: water should be above above 50° F (10° C), and ideally within 25° F (4° C) of the leaf temperature. Keep plants away from open windows in the fall, and if you have your plants outside, be very careful about seasonal changes. Bring plants in if the temps are expected to go below 15C…just to be safe.
Images of Phalaenopsis Leaf Damage – Mesophyll Cell Collapse
(possibly caused by cold damge, microfungus or viral infection)
Lack of Water – Phalaenopsis Symptoms
In the home, the main reason plants die quickly is because they’re not hydrated. Phalaenopsis can suffer dehydration from either under-watering or over-watering (which can kill the roots). A lot of online resources on ‘how to grow phals’ are geared toward people who have greenhouses or who live in humid areas. If you live a dry climate (under 60% humidity) like I do, then you need to pay close attention to the below water-related issues. It’s good to know: lack of water will likely affect our plants more drastically than someone who lives in an ‘ideal orchid climate’.
Your Orchid is not a cactus – don’t grow your orchid like it is one! A lot of online sites stress about the importance of “not over watering”, but if you’re watering once a week, you’ve got to make sure your plant is doing well and getting sufficient water in the first place or it’s just going to die a slower death. I sometimes have to water two (occasionally three times in a week)! Over watering is less likely to happen if you have the proper medium — you can read more about proper potting and watering methods here.
3 Signs and Symptoms Your Phalaenopsis is Not Getting Enough Water:
1) Floppy Phalaenopsis Leaves, or Worse Shriveled Leaves
Well-hydrated Phalaenopsis have leaves that are firm and can support their own weight. Signs of underwatering include: pale and droopy leaves. In the worst cases of dehydration, the leaves can split in the middle, and/or start to shrivel. There is an exception: new leaves that are reaching the end of their growth are often thin and cannot support their own weight. This will resolve, but you may want to support the tip of the leaf if the center starts to buckle from the weight of the rest of the leaf. New leaves will finish filling out generally in a month or so.
If a plant has lost too much water and the leaves have drooped or shriveled heavily then they generally will not regain their original plumpness even if you resolve the hydration issue. Future leaves will grow out firm and plump provided the plant doesn’t become heavily dehydrated again.
2) Wrinkled “Prune Finger” Phalaenopsis Roots
Dehydration starts to show up in aerial roots (the exposed roots that grow out of the pot or roots that grow from the stalk of the orchid) when they start to wrinkle. A hydrated Phalaenopsis should have roots that are round and plump, not shriveled and wrinkly.
Roots have four ‘phases’ of hydration:
1. When they’re dehydrated and the roots shrivel and look like ‘prune fingers’ (when your hands have been in water too long). This last phase of dehydration is a good indicator that you’re past-due for a good watering.
2. When they are dry and whitish-grey, and are in need of water.
3. When just watered, fully hydrated, and holding water they become a dark green colour.
4. When they’re happily hydrated and the roots are fat, round, and plump and in various between stages of green and white (in the pot, green-above the pot, white).
Your phalaenopsis roots will show signs of dehydration before the leaves will. If the roots on your plant are looking wrinkly, GET THEM WET! When I water, I spray all the leaves, and the roots. Again, for more information on how I water and for general care of phals read this post Phalaenopsis: Care, Culture and Tips to Keep Your Orchid Reblooming.
3) Lack of Roots Altogether
When you’re buying a new Phal, take a look at the roots. If they’re in the substrate, gently try to lift the plant out of the pot and see what the roots look like (this is why clear/semi transparent pots are very helpful). The roots should be green or whitish (as mentioned above). A little shriveled is also okay, but the majority of the roots should not be black/brown and spongy. If they are, it’s a bad sign. It’s a sign that the root system is suffering from root rot. It’s important to recognize this because it can be difficult (take a year or more) to bring an orchid back to blooming health if you’re starting out with no roots.
If you’re new to growing orchids, I would not recommend buying plants without healthy roots; it becomes a long process that doesn’t give you any reward for a long while.
I bet that the largest killer of home-grown phals is root rot. Root rot happens when a plant’s roots are not provided enough airflow and bacteria grows and kills the root(s). This can happen if you let them sit in water for too long and the roots or the potting medium becomes water logged, or if the roots are growing in a medium that has becomes sour (old, wet and acidic), or if the substrate is too compact. Often times, when you buy an orchid from a garden centre or big-box retailer (Walmart/Home Depot/etc) they’re potted in very-tightly packed sphagnum moss. “But why would they plant them this way?” you ask? It’s two fold:
- The gardening business in general tends to be a business of consumption — if your orchids live forever, you don’t come back to buy more, right? The demise of your plants are in the supplier’s and reseller’s best interest.
- Large-production greenhouses (where your big-box retailer orchid was produced) have MASSIVE automated systems; the plants are misted many times per day, they’re kept at a very high humidity, and the plants are surrounded by very heavy air flow. They are produced in conditions that are ideal for orchid growth and they’re never soaked under a tap. When you get them home, your conditions are different and much more harsh. Your home is dry, and water is less available, this is why you have to water heavily and freely to help the plant uptake water. The first time you take your plant home and soak that sphagnum moss under the tap, it expands and absorbs all the water and immediately stops airflow in the middle of the root area–it only takes a few days for bacteria to start growing under these conditions, and your newly acquired plant risks root rot within the first week you’ve purchased it. Who knows, maybe that first heavy watering has already happened at the garden centre, or big-box retailer before you got it.
These reasons are why I always repot EVERY phalaenopsis the day I get it (even if it’s in bloom). Some people say you can lose a plant’s blooms to bud blast (a symptom a plant is under stress where they pop all the flowers off prematurely), but I’d rather risk losing the first set of blooms, rather than lose the whole plant. If bought it, it’s because I *really* like the flowers and I’d rather have it bloom again and again, rather than only see the flowers once. By the way, I also call bullshit on the bud-blast issue–of my over 20 Phalanenopsis plants, I’ve never had a plant bud blast, or die since I started practicing these care methods which includes immediately repotting new plants. If your plant suffers bud blast it’s likely because there are elements of its care that are out of line, not specifically that you repotted it.
How do you know if your Phalaenopsis is getting enough water?
One thing I’ve noticed with my plants is that when they’re well hydrated (especially the 2-3 days after I water), they almost appear to glow in the evening. This comes from a cell phenomenon where well-hydrated cells are swollen and reflect light. You’ll notice it on flowers more than you will on the leaves — you can check this for yourself. Take your cellphone, turn on the flashlight and shine it on the flower petals. As you move the light around and you’ll see sort of a giltter sparkle on the flowers. This will happen on leaves if they’re very hydrated too. This sounds silly, but to me this is the equivalence of an orchid smiling when it’s happy.
Light Related Phalaenopsis Issues
If your watering is good but your phal still isn’t actively growing your next challenge may be light! A lot of online resources deem phalaenopsis as ‘low light’ plants. The problem with this is our understanding of “bright” vs. “low light” because our eyes can see in very low light.
Let’s say for example, that you’re in a basement with some overhead potlights. That light illuminates the room and appears to be “low light”, but it’s actually SO LOW that your phal would die for sure, but that process would take months, or up to a year before it eventually bites the dust. When considering an orchid’s need for “low light”, we need to beware that this is actually quite bright by our visible light standards.
So how do we know if our plant is getting the right amount of light?
1. Signs a Phalaenopsis is Not Getting Enough Light
- Your plant grows slowly, only putting out a new root or two at a time.
- Your orchid either doesn’t bloom or if it does it only has a few flowers.
- The leaves are long and skinny compared to the previous leaves that grew before you got the plant.
- Finally (and this one’s harder to tell because it will depend on the species/hybrid you have), the leaves are very dark green.
2. Signs a Phalaenopsis is Getting Too Much Light
- You’re getting leaf burn — once a leaf is burnt, it’s irreversible.
*If you’re moving your orchid near a window, you should do so slowly over the period of a week or two. Putting an orchid that has been growing in dark conditions into a very bright window can sometimes burn the plant more easily than if you had moved it slowly.
- The plant’s leaves are pale-chartreuse or yellowish rather than green is a sign of too much light. Plants grown under too much light are generally stressed and won’t grow as quickly, their leaves will be shorter, thicker, and hard. The upper limit of phal leaf colour is about the same as a granny smith apple, but there are many species that have dark-green leaves that will never get this bright green color. Those darker plants under bright light can either burn or start to develop spots or banding when grown in ideal light.
- The leaves are turning red or purple. If you push the light past ideal on a plant that has red/purple flowers, it often means it has a lot of red pigment. That will sometimes show up in the leaf. If you see red or purple fringing on your leaves, it doesn’t necessarily mean that you should to switch to lower light; however, darker leaves will absorb heat faster, so be sure to check the leaf temp with your hand–if it feels warm to the touch, get your plant to a lower-light area before you risk burning the leaf.
3. Just the Right Amount of Light
- How do you know if your phal is happy? To start, it should always be growing! This is especially true in the spring, summer and fall; sometimes during the winter as daylight periods are reduced, your plant will stall. If it’s the growing season outside, your phalaenopsis inside should be in the process of growing either new leaves, new roots, or a flower spike. The only time I’ve experienced a lag in growth is immediately following the buds opening into flowers–sometimes they’ll open and not grow for a couple of weeks as they replenish the energy from blooming process.
- Leaves are vibrant and full looking, not dull.
- Light freckling, speckling, silvering, or colour-flushing (red or purple). It will depend on the parent lineage of the orchid you have, but in most cases adequate light is right around the level where your plant starts to “blush” in the sun; generally phals that don’t blush, will turn a vibrant green-apple colour.