Plant disease

(Question)

I have brown spots on my plants – the Rozanne and other geranium and dead nettle.
I think it might be leaf spot. Sheridan guy thought it was leaf scorch. What do you think and how might I treat it Thanks

(Answer)

The spots on both your geranium and dead nettle plants are most likely fungal leaf spot which can occur on both outdoor and indoor plants, Spotted leaves occur when fungal spores in the air find a warm, wet, plant surface to cling to and begin to reproduce.

Spotted leaves or the causal fungus need two things to flourish: moisture and poor air circulation.  Here are a few things you can do to rectify these problems:

  • Water plants in the early morning so the moisture will evaporate from the leaves.
  • Avoid overhead watering or water so that leaves dry before nightfall.
  • Thin closely-packed foliage.
  • Treat pruning and cutting tools with a 1:10 bleach solution after each use.
  • Rake and remove all debris from around your plants before leaf bud each spring.
  • Cut and remove diseased foliage in late fall (fungal disease) or early spring to remove source of disease.
  • Use recommended fungicide sprays for leaf spots.

For more in-depth information see any of the following websites:

https://www.gardeningknowhow.com/plant-problems/disease/plant-leaf-spots.htm

https://ag.tennessee.edu/EPP/Extension%20Publications/Plant%20Diseases%20Identifying%20Problems%20of%20Garden%20Flowers.pdf