Bacterial Leaf Spot Pothos Disease: 5 Causes, Treatment + Prevention

Pothos (Epipremnum aureum) are popular, tropical foliage plants that enhance homes, offices, restaurants, and any bright, indoor space. Their long vines with glossy, heart-shaped leaves, often flecked with gold, white, or light green are handsome classic specimens.

But sometimes, dark spots and dots can show up on those beautiful leaves, spoiling their looks. What are they and how can I get rid of them? There are several things that they could be, one of which is bacterial leaf spot.

Bacteria are all around us, living on surfaces everywhere, including Pothos leaves. When conditions are right, bacteria can multiply and get a foothold in the plant’s tissue. Their growth begins to make lesions in the leaves, and you have a case of bacterial leaf spot.

What Is Bacterial Leaf Spot?

Bacterial leaf spot is a general term for infections by various types of bacteria, mainly, Xanthomonas spp. and Pseudomonas spp. The species, Xanthomonas campestris, is the most common one that infects Pothos.

Infections by these bacteria are brought about by overly wet conditions that promote their growth and spread.

What Does Bacterial Leaf Spot Look Like?

Bacterial leaf spot pothos lesions usually start as small water-soaked spots, often on the edges of the leaves or between the leaf veins, and may or may not be surrounded by a yellow ring.

These spots may be yellow, reddish, brown, or black, and as the tissue dies, it may collapse and fall out of the leaf, leaving a hole.

As it spreads, the infection can cause the leaves to become distorted, yellow, droop, and eventually fall off.

Does My Pothos Have a Bacterial or Fungal Leaf Spot Disease?

To give your Pothos the right treatment, you will need to know whether you have a bacterial or fungal leaf spot disease.

Fungal leaf spot infections may appear as small black formations on the leaves surrounded by white halos. They can also cause the plant’s tissues to collapse and form holes and the leaves to become yellow, droop, and fall off.

If you’re unsure whether your Pothos has a bacterial or fungal infection, you may want to take a leaf sample to your local garden center or horticultural extension agent for diagnosis.

Five Causes of Bacterial Leaf Spot Disease

Indoor plants usually don’t come down with cases of bacterial leaf spot disease – they are more common on outdoor plants. If you have set your Pothos outdoors for the summer, bacterial leaf spot disease can result from the following conditions:

  1. Warm, humid, overly wet conditions
  2. Poor air circulation around your plant
  3. Watering from above and keeping the leaves wet
  4. Spreading from an infected plant to your plant by wind or splashes of rain
  5. When your plant is already stressed and in a weakened condition

Best Practices to Keep Your Pothos Healthy Outside

pothos with light shining on a wood table.

You can address the above conditions by following these steps to prevent bacterial leaf spot from taking hold of your Pothos.

  1. Limit the amount of exposure your Pothos has to warm, rainy weather. A long stretch of rain where the potting soil and plant stay wet for days can be a breeding ground for bacterial infections.
  2. Pothos plants need some humidity, but overly humid conditions coupled with a lack of air circulation can open the door for both bacterial and fungal infections. If your plant is outside, make sure that it is sitting in an area where it can feel a breeze on all sides.
  3. Don’t water your Pothos from above. Water the potting mix and keep the leaves and stems dry.
  4. If other plants in your yard are infected, remove the diseased branches and foliage. Keep your plant a good distance away from any infected plants or diseased foliage.
  5. When your plant is not at its healthiest and is showing signs of stress from watering issues, pests, or too much sun, it can be more susceptible to bacterial leaf spot. It may be best to keep your plant inside until its issues are resolved before bringing it back outside again.

Treatment for Pothos Bacterial Leaf Spot

Discard any infected leaves as soon as you see them so that they won’t have a chance to infect the rest of your Pothos. Then treat it with Streptomycin sulfate for plants that can be bought online or a bactericide containing copper.

Although it is primarily a fungicide, Neem oil does kill various types of bacterial plant diseases and can be used against pothos bacterial leaf spot.

Prevention: Best Practices for a Healthy Pothos

When your plant is healthy, it will not be as susceptible to bacterial leaf spot. Here are some care tips to follow:

Light – Set your plant in bright, indirect light and never in direct sunshine.

Temperature – Pothos is happy indoors at 65 to 75 degrees F, and outdoors at up to 90 degrees, but never below 50.

Humidity – They will tolerate household humidity down to 30%, but are happier in higher humidity. Pebble trays and humidifiers are a good idea, but make sure there is plenty of space and air circulation around your plant to prevent disease.

Soil – A loose, well-draining potting mix with perlite, cocoa coir, sand, or peat moss added will be fine for Pothos. Make sure your pot is a good size for your plant — not too big — and that it has at least one drainage hole.

Water – Don’t overwater! Only water your plant when the soil is dry and an inch or two down from the top and try to avoid getting water on the leaves themselves.

Fertilizer – Add a small amount of granular, slow-release fertilizer to the soil in the spring, or a half-strength liquid fertilizer three or four times during the growing season. You won’t need to fertilize pothos at all in the winter months when the plant is not actively growing.

Pruning – Keep your plant at a good length by pruning the long stems in between the nodes, and removing any damaged or diseased leaves.

Prevention sprays – Just to be on the safe side, it’s a good idea to spray the plant lightly every two or three weeks with Neem oil to keep diseases at bay.

Author & Editor | + posts

Nancy has been a plant person from an early age. That interest blossomed into a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Nancy worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.