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Orchid Leaf Diagnostics

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With the vastness of the size of the orchid family it is almost impossible to discuss all the differences between orchid species. Some orchid plants have small almost secondary leaves while others have green leaves as large as the blooms they produce. Some of the leaves on orchid plants are only growing before the bloom of the flower and seem to take second stage after blooms are produced on the plant. Other plants keep their leaves all through their flower blooming stage. But the one thing that seems to puzzle orchid growers is the many plant issues that surround the care of the leaves on their orchid plants. Here are some of the most common questions and some helpful answers.

Question: I have a Phalaenopsis orchid that has lost all of its flowers but the leaves look healthy and green. The branch that it grows on looks yellow despite the healthy green leaves. What can I do? Is the orchid dying?
Answer: The healthy green leaves are a good sign! Despite the yellow branch, the plant may be trying to rebirth itself which is something Phalaenopsis orchids do. Give it a little more moisture and some time and you may find that the plant revives itself.

Question: The leaves on my orchid have turned yellow. Should I be concerned?
Answer: This all depends on what leaves are involved. If the yellowing is occurring on the back bulbs, this is a normal part of the aging of your plant and should not be of concern. If the yellowing is occurring on the newer leaves, this could indicate trouble. Plants with this type of problem are indicating that they are suffering from either too much light or insufficient feeding. You can correct this by increasing the shading and applying orchid nutrients as directed. Other causes of yellowing can be from loss of roots and stress due to low temperatures.

Question: What should I do about the blacked area on the leaves of my plant?
Answer: Blackened area on leaves of an orchid plant can be caused by either sunburn, bacterial or fungal disease. If the black areas surface on the leaves following a hot sunny day, this may be the result of sunburn. If the orchid plant has exposure to direct mid-afternoon sunlight during the late spring through early fall, this can also scorch the leaves of some orchids. You can correct this by increasing the shading or by moving the plant to a less sunny location. If the blackened area does increases in size, this is an indication of bacterial or fungal disease. The best remedy for this is to cut off the diseased area with a sharp, sterile tool (i.e., razor blade or knife). Immediately after the cutting treat the plant with a fungicide like Physan 20.


Question: What causes the tip or ends of the leaves of my orchid to become blackened?
Answer: The most common answer to this problem is that blackened leaf tips may be caused by hard water, overfeeding with orchid nutrients or fungal disease. It is important to remember that the potting mix needs to be flushed out thoroughly with plain water in between feeding. Be sure to cut off any black tips on leaves to prevent the die-back from continuing to run back down the leaf. When cutting the leaves be sure to use a sterilized pair of scissors.

Question: What are the small reddish brown spots that are turning black on the leaves of my orchid? What should I do?
Answer: This is often an indication of a fungal infection. This happens because fungal infections are usually the result of warm temperatures, high humidity and low light levels. Your best course of action is to treat the plants with a systemic fungicide such as Phyton 27.