News of a new blight, which I had not heard about until people started talking about it on yesterday’s pesto threads:
A potentially fatal fungal disease called downy mildew has been attacking basil plants in New York, New Jersey, Ohio and Florida. Gardeners are worried that it could spread farther throughout the summer, turning delicate green basil leaves an ugly shade of brown, yellow or gray…
So-called basil blight is similar to late blight in tomatoes or downy mildew in cucumbers, squash and melons. McGrath says these are considered “community diseases” because they move easily. “If you have it in your garden, you can affect other gardeners and farmers because the pathogen can jump onto their crops and plants,” she says…
The sign of the blight, McGrath says, is the top of the leaf will start yellowing. But to really know the state of the plant, you have to flip the leaves over and look on the undersides.
“You’ll see a grayish, almost purplish dusty growth on the underside, sometimes turning to almost black — and that is all of the pathogen spores. And there are incredible production of them on the underside of the leaves,” she says. “The wind will pick those up and blow them off and the disease just keeps multiplying like crazy.”
McGrath says that if you see the blight, you could get rid of the leaves, but if you remove one, you’ll probably knock around the spores and they could get on other parts of the plant. She suggests making pesto on the spot with the healthy leaves when you see the first signs of blight.
This would be the year I decided to grow more than two basil plants. I’m planning to spend some time this afternoon spraying a product called Serenade on my plants. Don’t know if it will help with the basil blight, but it’s supposed to be a broad-spectrum fungicide, and I already planned to try it on the tomatoes, roses, and lilacs.