Crepe myrtles, sometimes called crape myrtles, are beautiful additions to any yard’s landscape. They are a very hardy plant, providing year-round color variety and act as an accent to an already manicured yard. However, as a homeowner, you may occasionally discover black mold on crepe myrtles. Today, we want to look at how we can fix this problem.
What is black mold on crepe myrtles?
If you’ve ever run across what appears to be a black, sooty-like substance on your crepe myrtles, it’s most likely black mold. It’s a fungus that grows due to “honeydew”, a slick sugary substance left behind by excessive insect growth.
To be clear, this isn’t a disease nor is it unhealthy for your tree. Rather, it’s simply an unsightly byproduct from extensive insect presence. Furthermore, it’s also not a major health concern for most people, even though we’ve all learned to avoid black mold. While they’re in the same family, sooty mold is technically known as P. aeruginosa and does not have the same anti-respiratory health issues as Stachybotrys chartarum (normal black mold).
What does sooty mold look like?
Black sooty mold, on crepe myrtles or anything else, looks like its leaves were kept too close to a bonfire. Another way to describe it: picture a simple candle in your home. Have you ever forgot to trim the wick and saw it smoking? If you looked up at your ceiling, you probably found a bunch of black dust.
Sooty mold looks exactly like that, only it’s outside and on the leaves of an otherwise beautiful tree. It can peel off in layers, looking as if the leaf is shedding a secondary layer of skin.
What causes black sooty mold on crepe myrtles?
Insects activity causes black mold on crepe myrtles. Specifically, aphids are the primary cause here in Gainesville, although other insects can cause problems in other regions of the country. Aphids are sap-sucking creatures. As with any creature, they have to process what they eat. That’s the honeydew we mentioned a moment ago.
Black sooty mold spores float in the air and then stick to this honeydew. From there, as with any mold, it grows based on the appropriate conditions such as heat, humidity, and sun/shade levels.
How do I know if I have aphids on my crepe myrtles?
Aphids reproduce rapidly. Once they take hold of a crepe myrtle they usually make themselves known pretty quickly. If you see drooping leaves or any yellow spots, these are both early warning signs that you’ve got an aphid colony growing.
Will black sooty mold kill my crepe myrtles?
In a word, no. It’s not a harmful mold — it’s just unsightly.
How to treat black sooty mold on crepe myrtles?
The first step is to clean the existing mold off of your crepe myrtles. Next, you’ll need to deal with the aphid colony using natural pesticides or natural predators. Either way, you’ll want to use natural solutions to protect your family’s and lawn’s health.
What are the natural ways to get rid of sooty mold?
First and foremost, water is your best friend to remove black mold on crepe myrtles. Mix some water with just a little bit of natural dish soap. Next, spray the leaves carefully. This will help remove this sooty mold layer and restore the beauty of your crepe myrtles.
The next step is to reduce the insect buildup. You can use either horticultural oil or neem oil, both of which are non-toxic pesticides. Be careful to only apply these at night. Application during the day can potentially amplify the sun’s UV effect.
An even more natural solution is to introduce an aphids’ natural predator, such as lacewing larvae and ladybugs. These insects can keep your aphid population at bay and your crepe myrtles free of sooty mold.
Finally, you can prune your crepe myrtles each February to remove any issues from the previous season. The best time to do this is right after the first flower bloom. Just don’t cut them below 8 feet. It may take longer to eliminate the mold, but this will allow the plant to grow healthier and help make the new growth resistant to bugs, diseases, and fungus.
Let us know if you need help!
As a part of our partnership with Gainesville area businesses, we’ll typically refer our customers to one of our recommended pest control companies. Proactively, we’ll also trim crepe myrtles in February to help maintain the long-term health of your crepe myrtles.
Interested in learning more? We’re just a quick web form away: contact us HERE to get a quote for our services!
Here are some great resources to help your lawn looks its best:
Ask An Expert: How to Prevent Mosquitoes In Your Yard This Summer
