Q. Thank you for identifying the scourge on my tomato plants as the wilt. You're so upbeat that it's easy to forget how heartbreaking gardening can be! In fact, your show today inspired me to plant some garlic! Will it be okay to plant my garlic where the wilted tomatoes now are, once I dig them up? I have SUCH a small plot of land to garden in. (By the way, should I put the wilted tomato plants in the garbage, or is that not necessary?) Thanks,
- ----Kathy in Hopewell, New Jersey
A. The first thing we have to do here is get our terminology straight. Wilts like the notorious Verticillium and Fusarium are soil-borne diseases that affect tomatoes that are grown in the same spot year after year, generally causing the bottom leaves of the plant to discolor and eventually fall off. Most cases are self-limiting, but a wet year and repeated same-spot plantings can kill entire plants. If you have one of the wilts, the diseased leaves should be trashed, not composted. (Diseased leaves of any kind should always be thrown in the trash.)
The healthy parts of such plants can be composted, although I'd still trash the roots in this case for good luck, as that's where these diseases begin. The only thing you need to do for next season if you got wilted is to mark your tomato growing areas carefully and not plant tomatoes in those spots again. If you have no other room, grow your next run of love apples in large containers filled with a 'professional' soil-free mix and compost. (See this previous Question of the Week for more info on tomato growing in containers.)
But I wonder if you instead mean the late blight epidemic that struck the East Coast this season, as New Jersey was hit hard and we've been talking about it a lot. Perhaps the worst disease that can strike tomatoes, late blight causes spots on leaves and fruits, discolors the stems and quickly kills the entire plant. Tomatoes and potatoes afflicted with such symptoms should be disposed of in sealed bags in the trash ASAP. No exceptions!
Although people use the terms interchangeably, wilt and blight are very different, and failure to promptly destroy blighted plants risks the infection of other people's gardens—and farms. The good news is that both types of illness are specific only to certain types of plants and its safe to plant garlic in those areas—after you carefully clean up all fallen leaves and fruits.
Q. Dear Mike: I have just read your excellent description of the Late Blight Crisis. Sadly for me, this awful disease struck my garden in mid-August. I was shocked to see how rapidly it spread, and how devastating it was to my previously healthy-looking plants. ALL of my tomatoes were infected, and half of the ripened and nearly ripened tomatoes were spoiled. I have read conflicting information about what to do now. Is it OK to eat or can the unaffected tomatoes? And do I need to do something to treat the soil after I remove the infected plants? Thank you,
- ---Claudia in Kent, Ohio
A. 'Luckily', I got hit by late blight as well, and lost all my plants with the exception of one in a big container that I'm watching like a hawk. I say 'luckily' because this meant that I could see up close and personal how unappetizing and nasty looking the affected fruits were. (I quickly sealed them up and trashed them with the plants.) Extension experts like Cornell's Dr. Meg McGrath (no relation) who have been tracking this disaster are urging some caution in eating and canning any healthy parts of infected fruits. Although this pathogen has no effect on humans, they worry that the injuries it inflicts may make the fruits more likely to pick up nasty little things that can make us sick through cracks and deformities.
Although I am typically a pooh-pooher of such overcautious advice, I believe I will take the high road here. I did get a couple gallons of perfect tomatoes, and like Dr. Meg McGrath, did not dispose of them. She's eating the few nice ones she got, and so am I. But this season gave me such shpilkes that I'm going to freeze any sauce I make from them. No canning this year, just to avoid any possible risk.
Your other question has a happier answer—the pathogen that causes late blight does not overwinter in soil, so cleaning up all the old leaves and fallen fruits from your blighted tomatoes should be enough. Potatoes, however, are another story. This is the same pathogen that caused the Irish Potato Famine, and it DOES overwinter on infected tubers. So if you grew potatoes, make sure you get every blessed one out of the ground, even if you saw no signs of problems in your garden. And don't replant any tubers from this year's garden—again, whether you saw problems or not. Let's all work to make sure that this year's heartaches are a 'gift' that WON'T keep on giving.
And whether the disease you faced was late blight or not, good garden sanitation is always in order: Remove any diseased or discolored leaves as soon as they appear (you'll be surprised at how much better your garden will look when you get compulsive about this). And again, always trash such material; don't risk putting it into the compost, no matter how good you think you are at birthing black gold.
And no matter what kind of plant, clean up all its fallen leaves and fruits at the end of the season—especially under fruit trees; a 'clean orchard floor' is the best way to prevent future problems. If the material looks healthy, compost it with lots of shredded fall leaves this fall. "If in doubt, throw it out."