ants on Rose of Sharon

(Question)

Ants are all over my rose of sharon buds, I think they’re ruining the flowers at the tips, sucking the life of the bud. There’s no sign of aphids that I can see, just these ants. When the flower had bloomed there were holes in it! Please let me know why I’m having this problem? I tried blasting them off with the hose but they’re back. They are on the monarda below the RoS too but only the RoS buds look bad. I do have patio stone near by the ants go thru the cracks. I know ants are good but this is not good! please help! Can it be aphids that are so tiny I can’t see them? Thanks!

(Answer)

Thank you for contacting Toronto Master Gardeners.

Rose of Sharon or Hibiscus syriacus may become infested with aphids or scale insects. Although you have not seen any, these can be tiny with various appearances and may be hiding on the underside of leaves, or look like a fuzzy cluster. Scales are small greyish insects on the stems or branches and appear as tiny bumps. These insects produce a sticky substance called honeydew that attracts ants. This is most likely the cause of your Rose of Sharon problem.  For suggestions to control these insects, please see an earlier post:  https://www.torontomastergardeners.ca/askagardener/rose-of-sharon-6/