What, if anything, should I do about the holes in my hibiscus leaves? Many thanks!
- Patty C.
This damage is caused by the caterpillar-like larvae of the mallow sawfly. I once had some friends over and was showing them around my yard. I had some hardy hibiscuses/mallows planted by my front yard pond that were blooming well, but the foliage was really chewed up. I figured I'd get chastised for allowing my plants to become so damaged. (I rarely have the time or inclination to spray my plants for pests unless absolutely necessary.)
When we walked up to the plants, I said, “I’ve really been wanting to show you these hardy hibiscuses. These are the new lace-leaf hibiscuses that have just come out. Notice the beautiful lacy effect of the foliage and how the light shines through.” Of course, there was no such thing. But, by the time I was done they all wanted cuttings.
The lesson here is that these plants can tolerate damage, continue to grow and bloom – even though the leaves are chewed up. But, to be honest, the holes do not really enhance the appearance of the plant.
To minimize additional damage there are control options - if you are willing to spray as needed through the summer when you begin to see new damage occurring. There is a good organic insecticide for this pest called spinosad. You will find this in various brands at your local nurseries and garden centers. Apply as needed following label directions.
Consumer Horticulture Specialist
The LSU AgCenter and the LSU College of Agriculture