We’re talking with customers everyday who are concerned that they have a fungus on their plants. My first thought is that it would be rare to have fungus this time of year since its so warm, windy, and dry. It’s much more likely to be a bug. Here’s how to identify and control.
Is it white and cottony on the stems and flower buds? If so, you have Mealybugs! They show up in the Summer on Hibiscus, Jatropha, Purslane, Salvia and many more of our plants. You can treat with organic Spinosad soap or Bee Safe 3-in1 Garden Spray – be sure to spray in the evening due to our high temperatures. We recommend spraying the plant once a week for 3 weeks.
Do your leaves look brown and speckled? Sounds and looks like a fungus, but this time of year, its most likely lace bugs on the underside of leaves. They are notorious for attacking Lantana. We’ve even seen some lace bugs on Zinnias and Persimmon trees this Summer. We recommend you cut your plants back one third to half, fertilize and then spray with organic Spinosad soap.
Do your Crape Myrtles look black and sooty? This is a tricky one: black sooty mold is a fungus, but it’s caused by insects. Aphids, scale insects, and whitefly leave behind a sticky residue (called “honeydew”) that black sooty mold grows on. If you kill the bug, then the soot goes away. Each of these can be controlled with organic Spinosad soap or Bee Safe 3-in-1 Garden Spray.
-DeAnna
Carolyn says
What do I need to use on a crepe myrtle that like like a fungus on top of leaves with bugs on the underneath of the leaves? Do I need to cu it back? It is a young plant that was planted in the spring of 2020.
Jesse says
Hi Carolyn – that’s the black sooty mold on top of the leaves and aphids/whitefly underneath the leaves. You can spray with Spinosad soap or Bee Safe 3 in 1. Be sure you are getting good coverage on the bottom of the leaves where the bugs are. Once you take care of the bugs, the sooty mold will go away.
Sylvia Franco says
What about the worm that attacks Mountain Laurel? What do you recommend I use?
Thank you
DeAnna says
Texas Mountain Laurel is the host plant for its own caterpillar from a moth. You can spray with BT aka Thuricide which is an organic caterpillar killer safe to use on all plants including vegetables. We carry it in a concentrate, Ready to use or ready to Spray.