Air roots, also known as aerial roots, are commonly found in orchid species that are epiphytic, meaning that they grow above the ground, such as on trunks of trees. These species of orchids, which grow in the rainforests in the tropics, do not root in the earth like terrestrial orchids.
Orchids that have air roots use their normal roots to attach themselves onto the side of a tree. They grow this way because they are trying to reach more light, since in the rainforests there is only stippled sunlight filtering through the tree canopy.
Air roots work by actively absorbing moisture and nutrients straight from the air around them. This is how the orchid can survive even without the traditional potting medium that most plants need for their resources.
One of the most common problems orchid owners encounter is when the air roots on their plants begin to shrivel.
Shriveled orchid air roots are a sign that an environmental factor is causing the plant stress, and you will have to figure out the cause of the problem before you can properly resolve it and save the plant.
The most common causes of shriveling orchid air roots are low humidity, not enough water, and too much water.
In this article, we will discuss each of these problems and how to fix them. So, if you are currently experiencing this problem and want to learn more, just keep reading.
Why are the air roots on my orchid shriveling?
The most likely reason your orchid’s air roots are shriveled is because you are keeping it in a room with very low humidity.
As we mentioned above, these orchids are native to tropical rainforests where the humidity is higher than other topographical regions on earth. They have evolved to use this high humidity to their advantage by developing the ability to absorb moisture from the air.
Orchids prefer humidity within a range of 40 to 70 percent in order to function properly. Anything lower than that for long periods of time will cause the air roots to dry out and shrivel.
If you suspect that your orchid’s air roots are shriveling due to low humidity, you will need to take some measures to raise the humidity around the plant.
If it appears to be dried out, try giving it a water bath for 20 minutes, using rain water or filtered water. Just make sure that the potting medium is able to drain well afterwards.
Once the air roots have turned a healthier green again after the quick bath, you will need to start some practices to aid with your plant’s humidity needs going forward, so that the air roots do not shrivel again.
You can keep a spray bottle of water at the ready to mist the roots once in a while, which will temporarily raise the humidity around the plant.
You could also use a pebble tray filled with water. Place the plant’s pot on top of the pebble tray and, as the water from the tray evaporates, it will add moisture to the air around the roots.
You can also choose to keep your orchid in one of the more humid rooms of your house, such as the bathroom or the kitchen. This is one of the simplest ways to keep an orchid happy without much effort.
Or, if you have other plants that also enjoy higher humidity, group the orchid together with them so that they can all create a microclimate around one another.
If you have the means, you can also buy a humidifier to automatically regulate the humidity in the room where the plant is kept.
If you live in a place where the air can be quite dry, a hygrometer will help to monitor your home’s humidity. This way, you can always be aware of when you need to take measures to increase it.
Not enough water
When you grow orchids in your home, they are usually grown in containers where the regular roots are covered with orchid potting medium and the air roots are left to grow out to the sides. The plant is usually watered whenever the potting medium feels dry to the touch. If you neglect to water it for too long after the potting medium has dried out, this can lead to symptoms of underwatering, such as shriveled air roots.
The air roots of an underwatered orchid will also turn gray in color, which is a stark difference from the healthy green color of well-watered orchid roots.
Another sign of an underwatered orchid, aside from shriveled air roots, is when the leaves look pleated, curled, or, in extreme cases, dry and crispy.
If you think that your orchid’s shriveled air roots are due to underwatering, you need to water the plant immediately. You do not have to use any drastic methods; just water it the same way you normally would. Restarting your regular watering schedule should be enough to save the shriveled air roots.
In order to prevent underwatering your orchid again, you need to develop good watering habits. Typically, an orchid likes to be watered once a week, but there are plenty of factors that you need to consider when it comes to watering frequency, such as the weather, season and climate where you live, as well as the species of orchid and the potting medium it is in.
The best way to know whether your orchid needs to be watered is by feeling the potting medium with your fingers and looking at the plant’s roots.
If the roots look white or gray, that means your plant is dehydrated and you need to water it. Likewise, if the potting medium is dry to the touch, water the orchid, but if the potting medium is still a bit damp, wait one or two days before checking it again.
Too much water
Another reason your orchid’s air roots may be shriveled is that the plant has been overwatered to the point that its roots have become compromised, or may even be dead.
Overwatering can come about from giving the plant too much water everytime you water it, watering it more often than you need to, using a potting medium that is too dense and compact for orchids, or not adjusting your watering habits according to changes in the weather, season or climate.
If you continue to overwater your orchid for a long time, it can lead to root rot. This is a condition caused by prolonged exposure of the plant’s roots to waterlogged potting medium, so that they are unable to dry out between waterings and cannot absorb oxygen.
Because the roots are always wet, this will encourage fungal growth, and will also attract other opportunistic pathogens such as bacteria.
The fungi and bacteria will cause the roots to rot and die, and over time they will become unable to function properly. The plant will thus be unable to absorb nutrients and water in order to provide for itself. This will affect the entire plant, including the air roots.
If the orchid is presenting signs that make you think that it is underwatered, yet after watering it the roots still remain gray or white, this is a sign that the problem could be root rot rather than underwatering.
If you think your orchid is overwatered, stop watering it immediately ang move it to a spot where it can get good air circulation. Do not water it again until you are sure that the potting medium has dried out.
If you suspect root rot to be the cause of the shriveling air roots, you will have to remove the plant from its pot and inspect all of the roots. Rotten roots will be brown or black, and need to be cut off with a sterile knife or pruning shears. Rotten roots may also feel soft and mushy to the touch.
Remove all the affected roots as well as any air roots that have shriveled or dried out, until only the healthy roots remain. Do not worry about the roots that you removed; the plant will be more than capable of growing new air roots once it has recovered fully.
Place the orchid on a dry surface for the roots to air-dry for a few hours. While you wait, prepare a new container with fresh orchid potting medium. Place the orchid in the center of the container and cover the roots with more potting medium.
Place the pot in a spot where the plant can get bright, indirect light for most of the day, and where it is out of reach of warm or cold drafts.
Going forward, only water the plant when the potting medium is dry to the touch. The only way to prevent its roots from shriveling due to root rot is to avoid overwatering.
These plants do well in bright light, but they do not like direct late-afternoon sunlight. If you are keeping the orchid indoors, it is best to keep it next to a north or east-facing window because these are the windows that let in less intense light.
If the only windows available in your home are letting in harsh light, you can still place the plant near them, but hang a sheer curtain over the window first. The curtain will diffuse the intensity of the light so that the plant does not get burned.
If you live in a place where natural sunlight can be scarce for a few months of the year, you can use a grow light to help your plant get the light it needs. Natural light is, of course, the best choice, but artificial light is a good alternative if natural sunlight is unavailable.
Ordinary potting soil or potting mix will not support the growth of orchids. As an alternative, you can purchase or make your own orchid medium, which may include a variety of unusual items such as moss or bark, cork, or even chunks of brick, all of which will allow the roots to breathe more easily. Your orchid will thrive in a slightly acidic environment created by the combination of the growing medium, water, and fertilizer.
The pot that you use for your orchid should also have drainage holes at the bottom to allow any excess water to simply flow out. This helps prevent overwatering and root rot by not allowing the water to be retained in the potting medium, which would leave the roots waterlogged.
Orchids require only a small amount of water. Their roots are highly specialized organs designed to absorb water very quickly; they require regular periods of drying in order to breathe, followed by periods of heavy watering.
During the summer months, give your orchid a thorough weekly watering. Allow the water to drench the roots and fill the pebble tray to the brim. I find it does not hurt to put the plant in the kitchen sink every once in a while and really soak it well. It will not die if you allow it to dry out afterward, so do not be concerned about that. It is possible for root rot to occur in orchids with overly wet roots, so this drying out period is necessary.
Conserve warmth for your plant in the winter and reduce your watering to once or twice a month, at the most. Mist it once or twice a week to keep it hydrated.
Temperature and humidity requirements
Tropical orchids like to have high humidity and good air circulation around their roots. Temperatures above 50 degrees but below 85 degrees Fahrenheit are ideal for orchid growth.
If you can provide a mild, warm, and slightly humid environment for your orchids, their blooms will last longer. Do not place your orchid in an area where it will be exposed to cold drafts or direct sunlight, such as near heating vents or air conditioning. These delicate flowers are harmed by dry air, direct heat, and cold temperatures.
During the growing season, give your plant a weak solution of a powdered or liquid fertilizer once a week. During the winter, do not fertilize it.
Orchids have air roots that are distinctly different from the roots that grow down into the potting medium. These air roots are able to absorb water and nutrients directly from the air around them in order to feed the plant.
Air roots are present in epiphytic orchids that are native to tropical rainforests. These orchids grow on the trunks of trees so that they can get higher off the ground and reach the light that filters through the canopy of treetops in the rainforest.
One of the most common problems orchid growers observe in their plants is shriveled air roots.This is a sign that there is an environmental factor causing the plant stress, which will need to be resolved as soon as possible in order to save the plant.
The most common causes of shriveled orchid air roots are low humidity, not enough water, or too much water.
The sooner you are able to determine the cause of the problem, the sooner you will be able to take the necessary measures to save your plant.
Image: istockphoto.com / Gheorhge