Early Blight Alternaria

Question

I knew we shouldn’t have purchased these stinkin plants.

1. Would it be best to get rid of them and buy new plants?
2. Is the entire bed of soil not bad as well, from the disease? Do I need all new dirt?
Thank you very much.
Tamara Hufford-Wong
Portland, Oregon

Answer 1

Alternaria is usually soil borne. This article should help
https://www.gardeningknowhow.com/plant-problems/disease/alternaria-leaf-spot.htm