Tomato Gardeners, Plant On! Late Blight Is Gone The fungus that killed tomato plants on the Northeast last year probably died during the winter, says Mike McGrath, the host of the weekly public radio show You Bet Your Garden. He says that late blight typically blows up from the South, where spores grow year round.
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Tomato Gardeners, Plant On! Late Blight Is Gone

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Tomato Gardeners, Plant On! Late Blight Is Gone

Tomato Gardeners, Plant On! Late Blight Is Gone

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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If you live in a part of the country where temperatures are creeping higher, or even if there's still snow on the ground outside your window, it's that time of the year when you start thinking about the garden. And if you happen to grow tomatoes, you have a lot to think about.

Last summer, tomato plants throughout much of the East Coast were hit with a devastating fungal disease called late blight. It's the same disease that led to the Irish potato famine in the 1840s. To find out more about the potential threat to this year's tomato gardens, we're joined now by Mike McGrath. He's the host of the weekly public radio show "You Bet Your Garden." Welcome to the program.

Mr. MIKE MCGRATH (Host, "You Bet Your Garden"): Why, thank you, Michele. Thanks for having me.

NORRIS: You know, this late blight was a real nightmare for tomato gardeners last year. How much of a threat does it pose for the upcoming garden season?

Mr. MCGRATH: Not as much of a threat, as long as there's cleanliness on the back end of the industry. Last year, the late blight outbreak was so bad because it actually began with infected plants, baby plants that were released into the trade all through - up and down the East Coast. So gardeners started out with dying plants, unfortunately.

NORRIS: If you had blight last year, how much eradication do you have to do this year? Can you use the same plant stakes, the same garden tools, the same sheers or do you have to throw all that stuff out and start fresh?

Mr. MCGRATH: Luckily, no to all those questions. Late blight typically occurs in the Northeast when it slowly works its way up by windborne spores from the South, where they grow year round. So, most years you start out with a clean garden 'cause the spores can't survive wintertime outside.

NORRIS: Those spores really travel quite a distance.

Mr. MCGRATH: They can travel 30 miles in a day if the wind is correct.

NORRIS: Now, if growing plants from seeds is something that you're able to do in your home garden, start them in the basement or in some sort of garden shed, is growing plants from seeds a foolproof way to avoid the blight or do you still have to worry about it coming in from the South or are those spores flying in from your neighbors' yard?

Mr. MCGRATH: Unfortunately, starting your own seeds is zero protection. I didn't buy any of my starts last year from any stores that had infected plants. I start all of my tomatoes from seed. But the wind and the weather last year just carried it from garden to garden with lightening speed. So, most people who were hit did not begin with infected plants. The spores blew into their garden from other gardens.

NORRIS: And for those who grow tomatoes, whether it's in the ground or in containers, what should they be doing right now to ready their gardens?

Mr. MCGRATH: Not readying their gardens, not rushing the season. One of the biggest mistakes people make - 'cause everybody wants to grow tomatoes. Tomatoes are the gateway drug to all of our gardening. The supermarket tomatoes are so terrible that even people who think they have a black thumb want to get out there and grow some of their own to get that childhood flavor of a fresh garden-ripe tomato that they remember.

Most people put their tomatoes out way too early. You want to put your plants out when the nights are reliably staying in the mid-50s. That's a tomato plant that's going to start life very happy and healthy. In the meantime, if you grow in flat ground, build raised beds. They drain better, you can grow twice as much in half the space.

In a bad year, a raised bed garden will survive where a flat ground garden will be devastated by poor weather. And find a source of good yard waste compost. This is the world's greatest soil amendment, disease preventer and natural plant food. Compost that's made from last year's fall, leaves contains every nutrient that we know of that plants need. And they can utilize these natural nutrients to fight disease with their own inner resources that chemically fed plants can't utilize.

NORRIS: Mike McGrath is the host of the weekly public radio show "You Bet Your Garden." Mike, thanks so much for talking to us and happy gardening.

Mr. MCGRATH: Thank you, Michele, and happy gardening to you too.

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