The following is the introduction to the last chapter in my new book How Orchids Rebloom. This intro explains what you will need to know to properly diagnose orchid (or any plant) problem.
DIAGNOSING AND SOLVING ORCHID PROBLEMS
DIAGNOSING A PROBLEM – “Is My Orchid Doing Ok?”
When you first start growing orchids, you learn things like how much light to provide, how to water, and what temperatures to provide. Over time as you acquire a few more orchids, you’ll need to learn how to repot them (luckily you have the book How Orchids Rebloom.
Then one day…you notice that one of your orchids doesn’t look quite right. A leaf is yellow, the plant isn’t growing leaves as big as it used to. You ponder, “Is my orchid doing ok?” The ability to recognize, properly diagnose, and correct a problem will greatly improve your success reblooming orchids.

I’ve answered literally thousands of “orchid problem” questions over the years and have distilled all of these questions into this Chapter and other parts of How Orchids Rebloom. This chapter will help you diagnose plant problems and get you started figuring out “What’s wrong with my orchid?”
I use language like “may be due to” or “could be”, because no book, including this one, cannot for sure tell you what is wrong with your orchid. Nobody can 100%, for sure, tell you what is wrong with your orchid, unless they are looking at it in person, or see a good photo of it. You may ultimately need to take your plant to an orchid specialist at a garden club, nursery, etc. and have someone actually look at your plant.
“Correlation Does Not Imply Causation”
Just because two events correlate or occur at the same time, does not mean that one caused the other to happen. For instance, just because you see a bug on your orchid when your orchid is looking sick, doesn’t mean the bug made your orchid sick; the plant might just be too cold, too hot, overwatered, etc. Correlation does not imply causation.
“Everything is Connected”
The problems you encounter are often not the result of one single cause. Multiple factors are often interrelated, and as is said, “everything is connected.” For example, lack of light will not only prevent reblooming for some orchids, but it can also increase the likelihood the pot stays too wet and the orchid additionally suffers from “overwatering.” Another example, is using a pot that is too large, which prevents air from reaching the roots, which increases the chances the roots rot.
What You Must Know
To start, the ability to differentiate between the oldest and the youngest leaves on any plant is a powerful tool to help you assess the health of that plant, especially with orchids. For instance, it is common for the oldest leaf of an orchid, or any plant, to eventually turn yellow and fall off. However, if any of the youngest leaves look damaged or discolored, something is definitely wrong.
Being able to discern the youngest from the oldest leaves will empower you to answer questions like: Should I be concerned that this leaf is turning yellow? Is this plant getting too much water? Where will I see the next flower spike?
You must be able to distinguish between the oldest and youngest parts
of your orchid plant to properly assess the health of your orchid plant.
Next, the ability to differentiate between healthy and dead roots greatly helps you assess the health of your orchid plant. However, the roots aren’t visible, unless the orchid growing in a clear plastic pot. So sometimes you will need to gently slip the orchid out of the pot and inspect the roots if you suspect a problem.
Healthy roots are firm, whitish-gray to greenish-white with a shiny green or reddish green tip. Dead roots are soft, dry and/or and mushy ranging in color from brown to gray to black. It is common for some of the oldest roots to occasionally die. However, if all the roots are rotted, the plant definitely has a problem. An orchid is far more likely to recover from its traumatic event if it still has some living roots.
Another way to assess the health of your orchid
is by taking it out of the pot and inspecting the roots.