|I saw your answer about potted petunias that wilt and die one by one. You said that it might be a fungus in the soil. My potted petunias were doing great, blooming, etc. but parts of the plant are now wilting & dying. How can I determine if it is fungus, and what type? Can the soil be treated? Can the fungus be killed? I do not see any pests (such as slugs) around the petunia plants. Thank you.|
|Petunias are susceptible to Verticillium wilt and it's easy to diagnose. Cut one of the stems and look for dark colored streaking within the tissue. You'll want to cut off an affected stem and then cut it in half long-ways. The streaking will be within the vascular tissues. If the cause is indeed verticillium, you should change the soil and clean the planters thoroughly with a 10% bleach solution before replanting petunias.
If you see no obvious signs of fungus or rot, your Petunias may be wilting for other reasons. The plants may simply be showing stress from heat and humidity. If this is the case, pinch out the wilting stems and foliage (back to healthy growth). Try to keep water off the tops of the plants, and allow the soil to dry somewhat between waterings. These measures should decrease humidity and encourage healthy new growth.
Good luck with your petunias.