If you thought the cold, dreary weather we've seen the last several weeks was your only worry when growing tomatoes this summer, think again.
A deadly disease to tomatoes known as late blight has come early this year, putting the vegetable at major risk, according to North Shore and other New England garden experts.
Late blight, which is the same disease that caused the Irish potato famine in the 1840s, is a deadly fungal disease. Once infected, the tomatoes are inedible and very contagious, although not dangerous to humans.
According to Dr. Cheryl A. Smith, a plant health specialist for the University of New Hampshire Cooperative Extension, the first sign of the disease was discovered in New York three weeks ago, and the disease has since spread to all six of the New England states, including parts of Northeastern Massachusetts.
"August and September are normally when late blight shows up," said Tim Lamprey of Harbor Gardens in Salisbury. "Rainy weather with cool temperatures, especially having plants wet going into the night, are prime conditions (and) why it's showing up so early."
Meg McGrath, professor of plant pathology at Cornell University, calls late blight "worse than the Bubonic Plague for plants."
"People need to realize this is probably one of the worst diseases we have in the vegetable world," she said. "It's certain death for a tomato plant."
The disease shows up as brown lesions or spots on the stalk of the plant as well as spotting on the leaves. When the spots turn to a blueish-gray color, that means that the disease is spreading. The fungus will also form spores that will fall off the leaves and land on the ground below. Next year, if a plant is planted in that same spot, it will become infected.
Major stores such as Home Depot, Wal-Mart, Lowe's and Kmart in all six New England states, as well as New York, have removed tomato plants from their shelves, McGrath said.
Most home gardeners and farms around the North Shore region have not yet seen signs of the disease.
But Lamprey warns they may find it when they re-enter their gardens this weekend and next. Due to the weather, a lot of people most likely have not been in their gardens lately to notice any of the signs of the disease. Lamprey said that tomatoes are the No. 1 crop for home growers, and once people are in their gardens inspecting the plants, he worries there might be a lot more reports of the disease throughout the region.
"It's a very serious disease," Lamprey said. "It is something that will kill tomato plants, and the worst part is that it will reoccur year after year if people don't take care of it. With conditions we have had, and if they continue, it could take only a week or 10 days for (late blight) to spread."
Lisa Colby of the Colby Farm in Newbury said they are aware of the disease, and they have been looking for anything and everything since it has been so wet this summer, Colby said.
"We've been on the lookout for it, and we're holding our breath, but so far so good." Colby said.
Lamprey said that Cornell University recommends gardeners completely pull the plants out of the ground if they become a major problem. He warns not to toss them into the compost because it doesn't heat up to a high enough temperature to kill the fungus, so the disease will continue to spread.
Lamprey stressed that the best action to take is to catch the disease as early as possible. He said gardeners can even treat the plants with fungicide before they show signs.
"If you wait too long, you're going to lose all the tomato plants," Lamprey said. "An ounce of prevention is worth a pound of cure. If you can stop (the disease) now, that will prevent it from happening next year."
Bill Freitag, owner of Country Gardens in Rowley, said they have not had any customers complaining of late blight so far.
"No specific complaints about the disease," said Freitag. "(But) they have complained the tomatoes are not growing, with a lot of rot on them."
Agriculture officials in the various states still are trying to determine where the outbreak started. One major grower, Alabama-based Bonnie Plants, supplies most of the tomato plants to big-box stores, but it is unclear whether the plants were infected before or after leaving the supplier's multiple greenhouses.
"There's no way in the world you can pin this on one plant company, but we just happen to be the biggest," said Dennis Thomas, the company's general manager.
"We've not been written up one time for any late blight disease that was confirmed," Thomas said, noting that Bonnie Plants sprays seedlings before shipping them to stores, but that doesn't happen after the plants arrive. He said the company was proactive in removing plants once the outbreak occurred.
Material from The Associated Press is included in this report.