It can be hard to read the signs that a plant is struggling. It’s easy to miss a slight wilting of the leaves or even slowing growth. But when you see your pothos leaves turning black, there can be no doubt in your mind! Something is amiss with the plant.
Anyone growing pothos (Epipremnum aureum) is familiar with the cheery beer-bottle green color of healthy pothos leaves. The foliage may be variegated with paler greens or yellows and still appear in the peak of health. But black pothos leaves ring alarm bells in any household.
We’re here to explain the issue and the easy steps to take to fix it.
Reason for Pothos Leaves Turning Black
I consider my pothos as “best friend” plants. Like a best friend, pothos are cheery, easy-going, in fact, the easiest of houseplants to have in your home. They are infinitely tolerant, thriving in partial sun and even shade, and shrugging off those times you just forget to water. I never fertilize my pothos, not even the ones that cascade three feet (1m) from a hanging basket.
That means that when a pothos is ailing, it’s a big deal. Yes, there may be an occasional yellowing pothos leaf or two without sounding an alarm. But when the cheery green leaves start turning black, you are looking at a plant in distress.
Root Rot - Overwatering
There are many possible culprits when it comes to black spots on pothos leaves, but - as is the case in most real crime shows - there is one primary suspect. If you are ever asked to bet on why a pothos plant is turning black, put your money on root rot.
Root rot in plants always sounds serious, like the black plague in humans. But the cause is the very common and banal practice of overwatering. Pothos, like all houseplants, like an occasional drink of water, and need it to survive, but they do not tolerate wet soil.
Something in human nature makes us want to provide over-and-above for our plants and pets, but it isn’t healthy for them. If you are obsessively watering your pothos every day or every other day, just stop. Only provide water when the top two inches of soil are dry.
How does this look in practice? I water my small pothos pots once a week, and my big ones twice a month. They are in the peak of health. Still not confident? Investing in an inexpensive soil moisture meter like this one from Amazon is a good place to start as you learn more about your pothos's needs.
Root Rot - Poor Drainage
Sometimes root rot is not necessarily an indication that too much water is flowing into the container, but that too little is flowing out. Pothos need water but they also need well-draining soil that allows excess water to flow out quickly. When the soil is heavy or the pot has too few drainage holes, pothos roots rot and the leaves turn black.
If your pothos leaves are developing black spots but you don’t water that often, check the drainage. Changing out the soil and making sure the container has generous drain holes are steps one and two.
If the situation has been going on for some time, the damage might be more serious. In this case, you may also need to remove the root ball from the container and check the roots. You can recognize rotting roots easily because they are dark and soft rather than white and crisp. Snip off the rotting roots and replant the root ball in fresh soil and amend the soil with perlite.
Acute Cold or Freeze Damage
Pothos are rainforest plants in the wild, temperate zones where the temperature stays above 60 degrees F and they never experience a freeze. They need similar growing conditions in your home to thrive.
If the temperature in your house (or wherever you keep the plants) drops below 60 degrees F (15.5 C), your pothos react by stopping all growth. If it gets even colder, the plant will experience damage. If the pothos is subjected to extended cold temperatures and especially frost, the leaves will turn black. That suggests cell damage from which the pothos may never survive.
What to do? Don’t expose your plant to cold temperatures and keep them away from any cold drafts. Instead, keep those lovely pothos in the warmest part of your house over winter, far from air conditioners and open windows. A simple device like the Govee indoor hygrometer and thermometer from Amazon will allow you to keep track of temperature and humidity fluctuations and make informed decisions.
If the worst comes to pass and the plant is exposed to frost, move the plant to a warm spot as quickly as possible and keep your fingers crossed. If only a few leaves are black, the plant is likely to bounce back. If most of the leaves are black, the plant may be beyond help.
Other Possible Causes
Some garden writers suggest that underwatering, overfertilizing, and direct sunlight can darken pothos leaves. Call me a nit-picker, but I think these excesses wilt the leaves and turn them brown and crispy rather than black. In general, keep your pothos out of direct sun, fertilize very infrequently if at all, and water when the soil is dry to the touch.
How about pests like mealy bugs, spider mites or scale bugs? These pests feed on the pothos leaves, and can cause sooty black mold and black-brown spots on the leaves. If this is your issue, check the plants frequently and take action whenever pests are spotted. Try blasting off the bugs with a hose. Alternatively a neem oil spray will take care of the problem. Our editors love Captain Jack's neem oil spray which is available from Amazon.
