If your coleus is dying, it means that there is an environmental factor that is causing the plant stress.
The first step in saving a dying coleus plant is to correctly determine the cause of the plant’s declining health, so that the treatment can be specific and seamless.
The most common reasons your coleus may be dying are overwatering, underwatering, not enough nutrients, being root bound, low humidity, mildew, not enough sunlight and too much sunlight.
In this article, we will discuss the possible reasons your coleus is dying, and how to save it.
Why is my coleus dying?
One of the most common mistakes made by coleus owners, or plant owners in general, is giving their plant more water than it needs. When a coleus is overwatered, the first noticeable sign is that the leaves will turn yellow. They will then turn brown if you let the problem go on for longer. This means the roots have begun to rot and are starting to affect the rest of the plant.
Coleus plants do not like too much sun. They prefer to be placed in the shade. Unfortunately, in the shade, the soil is not able to dry out very quickly; if you overwater the plant, the sun will be unable to help the drying process. This is even more serious in cases where the soil in the plant’s pot is not well-draining, or if the pot does not have drainage holes at the bottom.
If you suspect an overwatered coleus, you can save it by removing the plant from the waterlogged soil and checking its roots. If there are brown or black roots, they are rotten and you need to remove them using sterile scissors. Make sure you disinfect the scissors after each cut so that the healthy roots do not get infected by any opportunistic pathogens.
Lay the plant on a tray lined with a paper towel to allow it to air dry for a couple of hours. When the plant is dry, you can replant it in a pot with drainage holes at the bottom, using well-draining soil. You can improve the drainage in gardening soil by mixing in compost or sand. These materials will make the soil more porous and airy.
To avoid overwatering, know how to water your coleus correctly. Before watering, check the soil by touching the top inch. If the soil is dry, water the coleus, but if the soil is still damp, wait one or two days and check the soil again.
When a coleus is underwatered, its leaves will also turn yellow. But instead of being droopy as in the case of overwatering, the leaves on an underwatered coleus will be dry. Underwatering may not be as fatal to the coleus as overwatering, but you should still never allow the soil to dry out for long periods of time.
Saving an underwatered coleus simply requires you to generously soak the plant until you can see the excess water flowing out of the drainage holes at the bottom of the pot. Make sure all of the soil has been drenched so that all the little roots will be reached by the moisture.
Remove any dried foliage to preserve the plant’s aesthetic. When the plant has perked up, you can resume watering it regularly. Before watering, touch the top inch of soil. If it is dry to the touch, you can water the plant; if the soil is still damp, wait a few more days.
Lack of nutrients
The coleus’ can also die if it does not get the nutrients it needs to survive, and again, its leaves will turn yellow in this case. You can get the soil tested if you suspect a nutrient deficiency in your plants. You can try adding compost to the soil to enrich it, or you can simply replace it with fresh soil. When the soil in the pot has been the same for several years, the nutrients will become depleted and affect the plant.
You can also apply fertilizer to the plant; just make sure it is a slow-release fertilizer so that the plant does not get overwhelmed.
The roots are bound
Another reason why your coleus may be dying is if the roots have become bound around themselves, usually because the pot it is in is too small. This is most obvious when the roots start to spill out of the top of the pot. A root-bound coleus will turn yellow and stop growing unless you transfer the plant to a bigger pot.
Take the plant out of the soil and massage the roots gently to untangle them. Make sure the new pot is two inches taller than the old one so that the roots have plenty of room to grow into.
Coleus plants do not like the humidity around them to be too low, and this can result in browning leaves and, ultimately, death. They do well in parts of your house that are more humid, like the bathroom or the kitchen. You can also mist the leaves with water from a spray bottle so that the foliage does not dry out too quickly.
Another trick is to put a water tray next to the plant. As the water evaporates, the humidity around the plant increases. Arranging other plants quite close to the coleus also creates a microclimate for the plant with increased humidity.
If none of these works, you can always purchase a humidifier to do the job of keeping the plant’s surroundings humid.
Another reason why your coleus may be dying is because of mildew. This fungal disease causes the plant’s leaves to curl and droop. The spores of the fungus are purplish gray and found under the leaves, where you will also see the lesions caused by the fungus. Eventually, these damaged leaves will fall off. Be careful when handling the plant so that the spores do not spread to your other plants.
Make sure you place the plant in quarantine when treating it so that the infection does not spread. Inspect the leaves and remove those that are damaged or have spores on them. Make sure you dispose of the cuttings properly. If you can burn them, all the better. Do not throw them in the compost, because the spores can lay dormant until you apply the compost as fertilizer on new plants, which it will then infect.
When watering, do not water from the top of the plant, as the water splatter can transport the spores to neighboring plants. Water the plant directly at its base, wetting only the soil around the plant.
You can use a fungicide to kill the mildew. You may need to apply it several times to make sure that all of the spores have been killed.
Too much sunlight
The coleus’ colors will become dull and pale if they do not get enough sunlight. Plants need sunlight to make their food, so if they are deprived of sunlight for too long, they will start to die slowly.
To remedy this, transfer your plant to a spot where it can get about five hours of sunlight every day. If there is very limited light, especially during the winter, you can buy a grow light to help the plants.
Too much light
If the coleus gets too much light it will get sunscald, where the foliage turns white from the intense light. This happens because the chlorophyll in the plant’s leaves breaks down, making the leaves pale.
Remedy this by moving the plant to an area where it can get shade during the times of day when the sun is at its brightest.
If you place the plant near a window, move it away a few feet so that the light does not hit the plant directly.
Your coleus is dying because there is an environmental factor that is causing it stress. The first and most important step in saving the plant is to correctly identify the root of the problem so that you can treat it accordingly.
The most common causes of a dying coleus are overwatering, underwatering, not enough nutrients, the roots being bound together, low humidity, mildew, not enough sunlight, and too much sunlight.
Image: istockphoto.com / Srdjan Stepic