Monthly Archives: July 2018

Be on the Lookout for these Vegetable Garden Diseases!

Look out for these garden diseases! See symptoms? Please report!

Occurrence of a couple important diseases of vegetables and basil is monitored in the USA every year to be able to inform growers when they need to be prepared for them to develop in their crops. Their occurrence is variable and impact is great, thus the importance of monitoring, which is done primarily by plant pathologists working with growers. Gardeners can access this information, thereby also benefiting, and they can play a very important contributing role by reporting when these diseases occur in their gardens. Some gardeners already have been! I have lots of photos to help with identifying these plus other diseases at: and information about them at Make sure to take photos to document your report.

Late blight of tomato and potato. Occurrences are mapped at At this webpage anyone can sign up to receive alerts when late blight has been confirmed near them; the alert system is not just for growers.

Late blight on tomato

Downy mildew of cucumber, squash and other cucurbits. In addition to information about occurrences, at there is a map-based forecasting system predicting where the pathogen is likely to develop next. There is also an alert system gardeners can utilize.

Downy mildew on cucumber

Downy mildew of basil. Reporting presently is done to a spreadsheet at  A map-based webpage is being developed similar to that for the other two diseases.

Downy mildew on basil

Take advantage of these great resources, and please contribute reports to increase the value of monitoring and our knowledge about occurrences of these important diseases.

Dr. Meg McGrath is an Associate Professor at Cornell University’s Long Island Horticulture Research and Extension Center in Riverhead, New York.

Not sure of the disease on you vegetable plants? Contact our Horticulture Diagnostic Lab and drop off a sample for diagnosis. For current hours, visit: