There are many types of orchid diseases, but this list was put together to highlight some of the more common types of orchid diseases and how to identify, treat, and ultimately prevent. Orchids get a bad rap for being tough to take care of. When in all reality they are quite easy to care for, if the orchid owner is patient and diligent.
Starting with three topics that are common with orchid ailments including burns, rots, and pests. These are usually where you want to start. The next step is to identify which ailment your orchid is suffering from and for that we’ll talk about identification of the specific problem and what to look for. Lastly, we will talk about how you can treat and prevent those problems in the future.
Burns: You basically have three types of burn with orchids and those are sunburn, fertilizer burn, and freezer burn. All three have relatively simple prevention methods, but it some cases it might take a little time for your orchid to heal. So, make sure that you’re patient and don’t try to rush things.
Sunburn Identification – This typically happens with orchids that are either moved to new window in the house or put outside in the warmer months. The affected portion looks like a thin light patch with a dark ring. It can be present with a single sunspot or multiple tiny sunspots.
Sunburn Treatment – Obviously, the first thing that you want to do is to decrease the light that your orchid is receiving. Usually the best thing to do with a sunburn is to leave it untreated and let the orchid naturally heal itself. You want to check to make sure the damaged portion stays dry. If so, then you are fine and the orchid leaf is still providing nourishment to the overall plant. In some cases the wound will turn mushy and start to rot. If that is your situation, you’ll have to follow the rot treatment explained below.
Sunburn Prevention – Acclimate orchids slowly to new light conditions. Understand that different seasons produce different levels of light and adjust to those conditions. Generally, orchids are not a heavy light requiring plant and more often than not beginners feel like their orchids are not receiving enough light. So, they drastically increase light conditions and this is when Sunburn can happen.
Fertilizer Burn: This is another very common problem with beginner orchid growers. People feel that more is usually better and they will get quicker results from over feeding their orchids. Again, this is where the patience comes into play. Be careful to make sure that you’re not over fertilizing your orchids, if left untreated it can ultimately kill the plant.
Fertilizer Burn Identification – Some common things that you will see when you’re overfeeding your orchids are: lack of root growth, salt build up on potting medium, dead root tips, salt build up on pot, and brownish black dead leaf tips.
Fertilizer Burn Treatment – Basically if you start to see these symptoms you’re going to have to do an emergency repot. You want to remove all of the old medium as well obtain a new pot. Thoroughly rinse all salt build up off of orchid and repot with new medium and watch closely for a couple weeks.
Fertilizer Burn Prevention – There are a couple things that you can do to prevent this from happening, but the main thing is that you want to avoid over fertilizing your plant. The rule of thumb is to usually cut the recommended dosage in half and gradually move it up if necessary. Another thing you can do is to make sure that you give your orchid a nice rinse with plain fresh water including the medium and root areas after fertilizing.
Freezing: In some cases people don’t give their orchids the correct temperature that they need to survive. The problem with orchids that have cold damage is that they often don’t really show signs until they are brought to warmer temperatures. Most of the time if you’re between 65 and 80 degrees you should be OK.
Freezing Identification – Some things you want to look for if you suspect the orchid to have any type of freeze damage are: browning, surface wounds, sunken discolored spots, slowed growth, and accelerated rate of death.
Freezing Treatment – Make sure you allow the medium to dry completely and keep orchids in a humid, low light environment. Don’t let affected orchids have direct sunlight or expose them to extremely high temperatures. Again, be gradual with treatment and be patient to let the orchid heal itself. It’s like caring for someone with a cold. Just watch them and prevent them from getting worse.
Freezing Prevention – This is a tough one… keep your orchids in temperatures from 65 – 80 degrees Fahrenheit (depending on the need of the specific orchid).
Rots: Rots are extremely common and very deadly to orchids because they can spread from one orchid to another quite easily. With most rot problems the culprit is usually overwatering. We’ll talk about a couple types of rot and the first being Black Rot.
Black Rot – Black rot is pretty severe and if left untreated will ultimately kill the plant. The real problem with black rot is that if you’re watering an orchid with black rot and you have other orchids near by, the splash back can get on those other orchids and ultimately infect them as well.
Black Rot Identification – If you have massive black spots overtaking entire leaves you may have black rot. You can’t mistake the very dark color and it will usually be accompanied with a yellow margin around the edges. It can affect any part of the orchid, but usually starts with the edges of new leaves and works its way down to the roots.
Black Rot Treatment – The first thing you must do is quarantine the infected orchid away from any other plants. Once that is done, you’ll want to increase air circulation on the affected orchid. Raise the orchid off the ground to avoid any type of splash back. Use a sterile razor blade and cut well below the affected area. Allow the cut to dry and apply a fungicide to the cut area. You can use cinnamon combined with cooking oil to create a homemade fungicide paste that works quite well.
Root Rot – Another type of rot that is common with orchids is root rot. This happens often with new orchid growers due to overwatering. It occurs when the medium is broken down and the drainage is poor. This can kill your orchid if left untreated.
Root Rot Symptoms – You’ll first probably notice symptoms of root rot on other parts of the orchid. Leaves can become twisted, thin, and shriveled. The roots will be mushy, limp, and dead.
Root Rot Treatment – If you suspect that your orchid has root rot you’ll definitely want to repot with a new substantial medium. But first, you’ll want to remove affected areas with a sterile razor blade. Remove both affected roots and leaves. Apply a fungicide to cut areas.
Root Rot Prevention – Whenever you get a new orchid it’s a good idea to repot right away to check roots. Often, there will be a couple of dead roots and catching them early is really the way to go. Really, the most common reason for root rot is overwatering. Remember if you’re not sure if your orchid needs water, then wait another day or two… it’s always better for orchids to be on the dry side as opposed to being damp.
Pests: There are a couple of different pests that we’ll be discussing. The thing to remember with pests is prevention is key. There are a couple of things you want to do regularly. Make sure when purchasing a new orchid that you inspect it thoroughly, always clean up dead and discarded leaves, and avoid overcrowding of orchids.
Aphids – Aphids are common orchid pests and the real problem with aphids is that they reproduce quickly. They are a lighter color and are less than a quarter inch long. They can even develop wings to migrate from one orchid to another.
Aphid Identification – Aphids will attach to new growth areas, the undersides of leaves, or directly on the flowers. Your orchids will display poor or stunted growth. Aphids molt their skin, so if you see small white piles of flaky skin on your orchids, this could be a sign.
Aphid Treatment – You’ll want to contain the infected orchid first to prevent infestation. Take a cotton swap and dip it in 70% rubbing alcohol. Inspect the orchid and dab the cotton swap onto aphids to remove them. Repeat the treatment in seven to ten days. Regularly, wash the foliage with soapy water. Ants will probably be present along with aphids so you’ll also want to use a sugar-based ant bait to eradicate that problem.
Mites – These little guys are extremely tiny and barely visible to the naked eye. Since it’s so tough to see them, they usually can cause some pretty bad damage by the time they are discovered.
Mite Identification – Look for the bottom of the orchid leaves to get a silvery appearance. Also on the topside of the orchid leaves there can be small yellow dots. Some mites even spin webs across from leaf to leaf. The way to tell if you have mites is to take a clean white sheet of paper. Hold the paper underneath the suspected area of infestation. Then, take a magnifying glass and check out the remnants on the paper.
Mite Treatment – Mites are generally toughest on orchids in low humidity. So, the first thing you’re going to want to do is raise the humidity in the orchids environment. Then you can wipe your orchid down thoroughly with a soft clean cloth, and repeat that for a couple of days. If you have a large infestation you’re going to want to use an acaricide. These are especially for mite control. You’ll want to take that and apply a coating every four or five days and repeat that for seven applications. Make sure that the undersides of the leaves are covered well.
There are many common orchid diseases, but this is a good start for someone who may not be familiar with orchids, to identify and rectify their issue. Remember with orchids, it’s about gradually easing them into new environments and not over feeding or over watering them. Keep them in a well-circulated environment without an abundance of light or extreme temperatures and you will be able to prevent a lot of these issues from the start. When buying a new orchid, make sure to inspect it thoroughly to avoid bringing something home that may infect your other orchids. With a little attention and a lot of patience you can either resolve your orchid health issues or prevent them from ever happening in the first place.