When caring for potted plants in a greenhouse or at home, sometimes it can be tricky to tell if they are happy. That is why you need to know what are the first signs of problems.
Plants will try to tell us that something is wrong by changing leaf color. For example, yellowing of tomato plant leaves in a particular pattern can indicate nutrient deficiencies.
Most of the time type of yellowing helps to identify what nutrients your plant is missing. Although the yellowing of plant leaves is the most common sign of a problem, sometimes plant leaves are losing color.
It is normal for some plants, trees, for example, to lose green color in fall. However, if you noticed that there are transparent spots or that plant leaves are turning translucent, your plant is struggling.
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So, why are plant leaves turning translucent?
If transparent spots appear between leaf veins, it’s a sign that tropical plants are exposed to intense cold. However, if the lesions grow and leaf edges turn brown, it’s most likely bacterial of fungal disease. Moving a plant away from open windows helps to prevent transparent spots but there is no treatment for bacterial or fungal disease.
In this blog post you will find out what plants are prone to lose color and get transparent spots. We will also have a look at the most common causes of leaf discoloration and you will learn how to easily solve these problems.
Let’s dive in!
Why do plant leaves change color?
It is very important to identify nutrient deficiencies promptly, so you can eliminate the cause and treat your plant. Although most of the time nutrient deficiencies are caused by poor soil, pests and diseases can also account for the damage.
The most common symptom of iron deficiency is that leaf veins are turning dark green while the areas between the veins are turning yellow.
If you noticed that plant leaves have holes in them, that is damage from insects like slugs, snails and caterpillars.
Caterpillars (tomato hornworms) most of the time target tomato plants, so you have to know how to get rid of these bugs in a greenhouse.
Now let’s find out why are plant leaves turning translucent.
Reason #1 – Cold Draft
What is a cold draft? It is a current of cold air that is being drawn indoors. Cold drafts are especially dangerous for tropical plants.
For example, if you noticed that pale, transparent spots appear on Calathea leaves, the plant was exposed to intense cold.
Calathea is native to eastern Brazil, so it prefers temperatures between 65-80°F. Placing it next to the air-conditioner in summer can cause leaves to turn yellow and drop. Also, it is not a good idea to keep it next to the drafty window in winter.
However, if you noticed pale or translucent new leaves on your Calathea, that is totally normal. They are going to become darker with time.
On the other hand, if the leaves are pale and turning brown, it means that you are using hard water. Leave the jug of water overnight before watering and it should resolve the issue.
Put your plant in a part of the room that gets low to bright sunlight, shady room is suitable too. Place it away from open windows.
Short exposure to cold won’t do much damage, however, you need to prevent intense cold at all costs.
Reason #2 – Bacterial or Fungal Disease
Look at the transparent spots on your houseplants carefully. Monitor them for a couple of days and ask these questions:
- Are the lesions growing?
- Are the leaves’ tips or edges turning yellow or brown?
If you answer ‘Yes’ to all these questions, your houseplant has a bacterial or fungal disease.
If the edges of the leaves turned brown, then the plant tissue is dead. Sadly, there is no treatment for a bacterial or fungal disease.
In this case, you need to remove the affected leaves and discard them. Do it as soon as possible as there is a chance that the disease can spread.
Sometimes the little translucent spot can appear on Orchids with dark dots in the center. Scale insects can actually cause these marks.
These insects suck the sap out of the leaves resulting in slow growth and yellowing of the leaves. Scale insects look like shell-like bumps on plant stems.
Alternatively, translucent spots with the dark border are a sign of leaf spot disease. Parasitic fungi or bacteria attack many species of plants resulting in multiple spots on leaves.
Use Physan fungicide to treat leaf spot disease. You can just spray it on the affected area.
If you noticed that your plant leaves have a white coating it can be due to fungus causing powdery mildew.
However, if the leaves themselves lost color and turned white, it can be due to low light or ozone damage. To find out why are plant leaves turning white, click here.
Do water droplets burn leaves?
For many years gardeners were advising not to water plants in the middle of the day. That is due to the fact that water droplets on leaves can act like magnifying lenses concentrating the sun’s rays.
That would result in transparent spots which are sunburns. Sometimes the whole leaves would turn white and drop.
The common myth that water droplets can burn leaves when watering in the middle of the day is now debunked!
Scientists conducted experiments on both smooth and hairy leaves to find out if water droplets can cause scorch marks.
They found that any heat that got into the leaf was straight after transferred to the water. As the result, water got warmer and evaporated itself.
Therefore, no scorch marks were formed even in the midday sun. The same applies to hairy leaves too.
Moreover, researches found that plants have photoreceptor UVR8. It stimulates a variety of cellular responses to produce chemical sunscreens.
They can absorb harmful UV light, in particular UV-B radiation. In other words, plants can create their own sunscreen!
When leaves change color they are trying to tell that you are doing something wrong.
Keeping tropical plants next to windows can result in prolonged cold drafts that cause pale, transparent spots between leaf veins.
All you need to do is to put a tropical plant away from an open window where it can get low to bright sunlight.
Sometimes bacterial and fungal diseases can cause a plant to lose color and become translucent.
If that happens, you need to remove the affected leaves and dispose of them. It can help if the disease has not spread. Unfortunately, there is no treatment for these diseases.
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Let me know in the comments section if your plant is losing color so we can find a solution!
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Happy Growing 🙂