How to Get Rid of Sooty Mold on Plants

Have you spotted a black covering on your plants? It's likely sooty mold. This fungus grows where sap-feeding insects leave sweet droplets. You can remove it and bring back your plants' beauty. Here's how to beat sooty mold.

What is Sooty Mold

Sooty mold is a black, crusty or powdery growth on plant parts like leaves and stems. It forms when a fungus feeds on the sweet secretions left by insects. These insects, such as aphids, scale, and whiteflies, contribute to the problem. They leave behind sticky honeydew, which attracts the sooty mold.

This fungus makes the affected plants look dirty and covered in soot. Additionally, you may notice the insects themselves around the plants. These bugs are the ones leaving the sticky honeydew, which, in turn, feeds the sooty mold. So, in short, sooty mold is a sign that your plants are under attack.

It's crucial to get rid of sooty mold by fixing the pest problem. You can use horticultural oil or neem oil to fight off the pests. Sometimes, you might need to apply these oils every two weeks to keep the pests at bay. A soapy water wash can also help remove both the mold and some pests. This approach protects the plants from further damage.

Sooty mold is common on specific trees and shrubs, like hackberries, elms, and hollies. These plants get covered in the mold when attacked by bugs that feed on their sap. If the mold worsens, your plants might suffer. They could lose leaves or even limbs because this mold stops sunlight from reaching them properly.

While sooty mold messes up the look of your plants, it mostly just affects their appearance. It doesn't cause direct harm. Yet, if the issue gets bad, it can interfere with a plant's ability to make food. This could lead to the plant wilting or dying. Sooty mold loves sunny and dry conditions, the same weather that boosts insect activity. This creates a cycle where insects make more honeydew, leading to more mold growth.

See also
How to Keep Bees Away from Oriole Jelly

Identifying the Pest Problem

Sooty mold often appears with sap-feeding insects like aphids, scale, or whiteflies. These bugs suck plant sap and leave behind honeydew. The fungus grows on this sugary waste. To remove sooty mold, you must first tackle the insect problem.

Observe for signs of:

  • Aphids - Small green, yellow, or tan insects
  • Scale - Small turtle-shell-like insects
  • Whiteflies - Tiny white flying insects

To get rid of sooty mold, control the pest insects. You can use insecticides or other methods. Stopping the honeydew will eventually remove the mold. High numbers of these insects often point to the cause of sooty mold.

Impact on Plants
Small, soft-bodied insects that come in a variety of colors, including green, yellow, black, and red.
Aphids feed on plant sap, causing leaves to yellow, curl, and become distorted. They also excrete honeydew, leading to sooty mold growth.
Scale Insects
Small, hard-shelled insects that resemble tiny turtles or bumps on stems and leaves.
Scale insects feed on plant sap, weakening the plant and leading to the production of honeydew, which facilitates sooty mold growth.
Tiny, white, moth-like insects that fly up in a cloud when disturbed.
Whiteflies suck plant sap, causing leaves to yellow and wilt. They also excrete honeydew, contributing to sooty mold problems.

How to Get Rid of Sooty Mold on Plants

Sooty mold often shows up on plants as a black fuzzy coat on their leaves and stems. But you can solve this problem and stop it from coming back. The trick is to deal with the bugs first. They suck plant sap and leave honeydew behind for the mold to grow on.

To begin, control the bugs. Then, tackle the mold on your plants. A good way to do this is by using insecticidal soap. Spray this solution on the leaves and stems to break down the mold. This makes cleaning it off later much easier.

After the soap sits for about 15 minutes, rinse your plant with a forceful blast of water. The mold should start to come off. For heavy mold, you might need to repeat this cleaning step a few times.

See also
How to Treat Spider Mites on Indoor Plants

But that's not all. You also need to think about how to keep the mold from returning. This means making your garden less appealing to those sap-eating bugs. Finding natural ways to keep these pests away is best.

By dealing with the mold and the bug issue, you can make your plants healthy again. Follow these steps and you can get rid of sooty mold. Plus, you’ll know how to stop it from coming back.

Removing Existing Sooty Mold

First, you need to deal with the pests that cause sooty mold on plants. Sooty mold comes from bugs like aphids and whiteflies, who leave sticky honeydew. This honeydew attracts a black fungus that makes the plant look unsightly.

Start by making a soapy water mix to clean the mold off. Mix 1 tablespoon of dish soap with water in a spray bottle. Let it sit on the plant for 15 minutes to soften the mold. Then, rinse it with a strong stream of water from a hose.

This cleaning process might take several tries. Go gently, so you don't hurt the plant. If the mold keeps coming back, you must control the bugs that cause it.

Stopping the pests is key to keeping sooty mold away. You can use chemicals, or natural methods, to get rid of these bugs. This will stop the mold from growing back.

Preventing Future Sooty Mold Growth

The key to stopping sooty mold is by dealing with the bugs that make the honeydew. This honeydew feeds the mold. You need to find and treat insects like aphids, scale insects, or whiteflies on plants with care.

After fixing the insect problem, less honeydew means no food for the mold. So, any existing sooty mold will go away. Keeping plants healthy and watching out for pests helps stop sooty mold.

Sooty mold comes from fungi that eat the honeydew left by bugs. It can cover plants thickly and move between them by water or air. Hot, dry weather helps sooty molds grow.

For stopping sooty mold from coming back, gardeners should do a few things:

  1. Treat the plants for insects like aphids with special care. Use insecticides or other control methods.
  2. Keep plants healthy. Good spacing, watering, and weed control make them less attractive to bugs.
  3. Cut plants back in January and February to avoid new growth that might get infested.
  4. Use bait or sticky tape to stop ants. They protect bugs that make honeydew from getting eaten.
  5. Try using insecticidal soap or neem oil as part of a smart plan to control bugs. It's called integrated pest management.
See also
How to Keep Cats from Spraying Outside Home

Looking after your plants well and dealing with pests can help very much. By doing this, you can keep your plants looking great and healthy.

Sooty Mold on Non-Plant Surfaces

Sooty mold doesn't just target plants. It also troubles non-plant items like outdoor furniture and swing sets. These items can get a black film of this mold if they're under trees or plants with pests. These bugs leave a sweet, sticky stuff called honeydew on the plants. Sooty mold loves growing on this sugary substance.

Cleaning off sooty mold from these items needs a strong solution. A mix of powdered detergent, bleach, trisodium phosphate, and water works well. Make sure to scrub hard and wear rubber gloves. After removing the mold, solving the insect issue stops more mold from growing.

Keeping outdoor things clean is key to stop sooty mold. Tackling the insect issue first stops the main cause. Homeowners can then use the right cleaning methods to get rid of the mold. This helps protect outdoor spaces from looking bad or getting damaged by sooty mold.


The first step in dealing with sooty mold is to find and fix the insect issue. This includes bugs like aphids, scale, or whiteflies, which leave behind a sugary film that sooty mold likes. Use insecticidal soap to get rid of the mold, and then rinse the plants well to remove it.

You might have to do this more than once, every week until the mold is gone. Keep an eye out for pests and act fast to stop new mold.

By taking these steps, you can save your plants. It's all about keeping the bugs in check and cleaning off the mold. Prevention is always the best defense against sooty mold.

Was This Helpful?
Spring Portal Blog