Garden and greenhouse growers in Pennsylvania have been advised on how to deal with infected plants.
An article in the Philadelphia Inquirer suggested affected species can be spotted by lesions that appear greasy and a mix between green and brown in colour.
It said plants in the garden and greenhouse should be checked on a daily basis to ensure they stay healthy.
The article said: "If you see signs of blight, carefully remove infected plant, place in a plastic bag, set the bag in sun to cook spores, then put in the trash."
It advised against composting them as this could lead to infection of other varieties in your collection.
Spores can be carried by wind and affect not only your own garden, but those belonging to your neighbours the article concluded, stating that failure to act could cause a widespread problem.
Meanwhile, UK gardening magazine Grow Your Own recently commented on the increasing popularity of using the greenhouse or outdoor space to cultivate fruit and veg.