Oh Snap! Just when we thought the tomatoes were finally growing and all we have to worry about is weeds and bugs, a new headache shows up. As if this season hasn’t been difficult enough, gardeners now have a new headache. Late Blight of tomatoes, peppers and potatoes has been confirmed just across the border in southern Ontario. The disease thrives in wet weather and hitchhikes on the wind. Since we’ve had plenty of both we should expect to see it here very soon.
Late Blight is caused by the fungus-like oomycete Phytopthora infestans. Symptoms often include wedge shaped dead spots on leaves and sudden blackening and wilting of entire leaves. “Phytopthora” is Greek for “plant destroyer,” but don’t worry, several products can control this one if used properly.
What does all this mean? You should begin to watch for symptoms and apply protective materials to solanaceous crops such as peppers, tomatoes, eggplants and potatoes NOW. This is especially important in organic systems because products such as Serenade must be applied well before infection if they are to work properly.
You have a head start if you began by planting resistant varieties of tomatoes such as “Plum Regal” and the Mountain series. The key to control at this point is early and regular use of fungicides such as Fung-onil. Alternating a Copper product with the biological Serenade can also give good results. Be sure to follow all label directions. And be aware that you may have to apply every 5 to 12 days, depending on the product and the weather.
Be sure to stop by the nursery if you have questions or need more details. Remember, several situations can cause similar symptoms so accurate diagnosis is important for your peace of mind and your pocket. We can help you recognize the disease symptoms and develop an effective control plan that fits your needs.
Grossmans Garden & Home