5 Reasons Your Orchid is Dropping Leaves
Is your orchid dropping its leaves, and you can't seem to figure out why it happens? There are actually a few different issues that may arise that cause the leaves to start falling off your plant. In this article, gardening expert Melissa Strauss walks through the most common causes of leaves dropping from an orchid plant.
Orchids have notoriously picky maintenance needs for optimal growth. They are capable of great things, lots of growth, and stunning displays of flowers if they are happy. However, if their environment is compromised in one of a handful of ways, an orchid might let you know by dropping its leaves.
Does leaf drop always spell trouble for an orchid? There are actually a few common causes of leaf drop, and not all of them mean impending doom for your plant.
Before you break out those pruning tools and anti-bacterial/anti-fungal sprays, let’s take a look at some of the common reasons that orchids drop their leaves. You’ll learn exactly why it happens and what you can do to fix it once it starts. Let’s dig in!
The Short Answer
An orchid can drop leaves for many reasons, not the least common of which is a natural shedding of aged leaves as the plant produces new growth. However, dropping leaves and leaves that look diseased can be a larger issue that needs to be addressed quickly if you want to save the rest of the plant.
The Long Answer
There are several reasons why an orchid might be dropping leaves. It is important to inspect the plant and know the growth habits of the particular orchid in order to determine the proper course of action, if one needs to be taken.
Not all fallen leaves are the result of poor health. In fact, the plant just might be getting ready to direct energy to new growth or flowers.
Among the reasons that orchids lose their leaves, sometimes this is just the natural course of things. Deciduous orchids, like some species of Dendrobium orchid, lose their leaves seasonally. There is nothing that can be done to prevent this. It is simply the nature of the plant.
Aside from these deciduous orchids, all orchids will naturally shed their oldest leaves, typically once a year before they flower.
If the plant looks otherwise healthy, don’t worry if the oldest leases on the plant start to turn brown and eventually fall off. This is natural, and it allows the plant to redirect its energy to producing new growth and flowers.
Root rot, on the other hand, is a much more worrisome reason that an orchid may be losing its leaves. Their roots are very susceptible to fungal disease. They need a lot of air circulation, and they are intolerant of overwatering. This is particularly an issue for orchids kept indoors as their potting media takes longer to dry out.
If your orchid’s leaves are turning yellow from the center outward, and they get soft where they connect to the plant before falling off, you may have an issue with your roots. Healthy roots are green or white, plump, and smooth.
Dry roots will be gray and shriveled. Rotten roots are dark brown and mushy. The roots deteriorate and are no longer able to absorb the nutrients needed to support the leaves, and they begin to fall off, usually from the bottom upwards, or old growth first.
The only way to save an orchid from root rot is to repot and hope for the best. Once the leaves have been affected, there are likely to be very few healthy roots left. Remove the plant from its container and gently trim off the rotted portions of the root.
Allow the rest of the roots to dry out completely before repotting in a new potting mix. Adjust your watering schedule so that you are only watering once per week, and make sure there is good air circulation around the plant.
The ultimate cause of leaf fall from root rot is nutrient deficiency. This can happen for other reasons as well, and the result is the same. Leaves will turn yellow and soft near the plant, and eventually, they will fall off.
Orchids love fertilizer. Because they do not derive much in the way of nutrients from their potting medium, they need to be fertilized regularly, or you run the risk of a sad, unhealthy plant.
As a good practice, orchids should be fertilized every 1-2 weeks while in growing and flowering seasons. Fertilize every 3-4 weeks when dormant.
Another cause of nutrient deficiency is insect infestation. A bad enough infestation of spider mites, aphids, thrips or mealybugs can drain a plant of the nutrients it needs and cause the leaves to weaken and fall off.
To avoid an insect infestation, make a regular habit of inspecting your orchids’ leaves, as this is where the first signs will show up. The earlier you catch an infestation, the better chance you have of preserving the plant.
There are several different diseases that can cause orchids to drop their leaves. Let’s take a look at the most common diseases you may encounter, as well as how to treat them.
Bacterial Soft Rot
Root rot isn’t the only disease that causes leaf drop. Bacterial soft and brown rot is a disease which causes rapid destruction of an orchid.
Leaves will initially turn yellow and then black and rotten before falling off. If this disease strikes, it is imperative to act as quickly as possible.
Remove all affected tissue and treat with a bactericide. Copper compounds work very well. As a home remedy, hydrogen peroxide and bleach are valid treatments.
The disease is waterborne, and it is usually transmitted during watering when droplets splash from one plant onto another.
Bacterial Brown spot caused by the pathogen Pseudomonas is another issue for orchids and in particular, phalaenopsis orchids. While it is rarely fatal, it can cause some nasty spots and decay on the leaves.
Any infected tissue should be removed immediately, and the plant will need to be treated in the same manner as with Bacterial Soft Rot.
If your leaves are turning pale and shriveled or wilted, there is a chance your orchid has Fusarium Wilt. This disease makes it difficult for the plant to transport water to the leaves and can kill an orchid in a matter of a month if severe enough.
All infected parts of the plant should be removed, and the remaining treated with a fungicide. This disease is usually a hygiene issue, so be certain to clean your tools well before and after use.
Collar Rot, also called Southern Blight, is another fungal infection that affects the roots, pseudobulbs and leaf base. The bases of the leaves will turn a pale yellow before falling off. This should be treated in the same way, by removing affected tissue and treating it with fungicide.
There are a number of other diseases that can cause damage to orchid leaves. Brown Rot, Anthracnose, and Phyllosticta are three of the more common types.
All of these manifest first as spots and shriveling of leaves and should be treated in the same fashion. Start by trimming away infected tissue, then treating with copper-based fungicide, and maintaining good plant hygiene.
It can be difficult to bring an orchid back to health after a fungal or bacterial infection as it is difficult to remove all infected tissue, and any left intact can spread. The best prevention for these issues is to manage your environment properly.
Orchids like to be in warm, humid conditions. Don’t make the mistake of keeping the humidity high while the room is too cool, or fungi will grow.
Proper air circulation also goes a long way in preventing fungal disease. Always isolate a plant that you suspect is infected by a pathogen or fungus, as this is the best way to stem the spread.
Before you run to the store for a fungicide, inspect your orchid, its foliage, and any visible roots for signs of pests and diseases. If none are present, a little fertilizer never hurt an orchid.
As a good rule of thumb, though, if you are an orchid grower, a copper-based fungicide and some neem oil are great items to have on hand if the time ever comes that you need them.