White sticky spots - Ask Extension
Hello!
All of the Mexican Petunias in our back yard look dry and have white spots on the leaves.
Knowledgebase
White sticky spots #812011
Asked September 23, 2022, 8:26 PM EDT
Hello!
All of the Mexican Petunias in our back yard look dry and have white spots on the leaves.
Travis County Texas
Expert Response
The white "stuff" is actually a tiny microscopic mite called Eriophyid (Acalitus ruelliae). You don't need to use any chemicals to control them. If you did nothing the plant would be fine (in most cases).
If you want, you can prune out the infested parts of the plant and put it in the city yard waste collection bin. Be sure to sanitize your pruners after each cut. You can make a 2% solution of bleach water (1 teaspoon of bleach per cup of water) and either put it in a spray bottle or bowl. Then spray and wipe your pruners with each cut, or dip and wipe them. That way you won't accidentally spread them to new areas.
Something else you can do is spray them with insecticidal soap, (I use regular Seventh Generation dish soap). Soapy water kills most insects. You can spray the leaves (make sure there are some suds) and then rinse the plant well with the hose.
Ruellia (Mexican Petunia) is a hardy plant, so it'll be fine!
Best,
Brittany
If you want, you can prune out the infested parts of the plant and put it in the city yard waste collection bin. Be sure to sanitize your pruners after each cut. You can make a 2% solution of bleach water (1 teaspoon of bleach per cup of water) and either put it in a spray bottle or bowl. Then spray and wipe your pruners with each cut, or dip and wipe them. That way you won't accidentally spread them to new areas.
Something else you can do is spray them with insecticidal soap, (I use regular Seventh Generation dish soap). Soapy water kills most insects. You can spray the leaves (make sure there are some suds) and then rinse the plant well with the hose.
Ruellia (Mexican Petunia) is a hardy plant, so it'll be fine!
Best,
Brittany
Thank you! It's a relief to hear the plants are hardy and will probably survive despite my attempt to care for them.
