Friday, June 17, 2011

The Fungus among us; early blight on tomatoes

This is not so good. Not so good at all. Some of our tomatoes are showing signs of early blight, which if left untreated could potentially decimate not only our tomatoes, but also our beans, cucumbers, eggplant, and peppers. We have also started to see signs of powdery mildew on our roses and our mystery squash plant.

Brown spots and yellow of leaves are signs of early blight. Yellow Pear Cherry Tomato

Last year when we had this problem, I was not quite as serious about the garden, and maximizing my yields as I am now. This year, I am really hoping to have some beautiful produce to sell at the market, and I saw how badly this and other fungus can affect our plants so I want to prevent it from spreading throughout this plant and to other plants.

Powdery mildew on mystery squash

There are several things to consider when trying to prevent the spread of fungus:
  • Plants should be rotated throughout the garden. Once a plant is affected with early blight, you should not grow other susceptible plants in that area for 3 years.
  • People can be one of the main causes of spreading this disease. If you touch a plant that is infected then it is important to wash your hands well before touching unaffected plants in the garden.
  • Tools should be disinfected after coming in contact with affected plants.
  • Plants need good circulation to help prevent the spread of fungus.
  • Don't add infected foliage to your compost
  • Avoid wetting the leaves when watering your plants, as fungus find wet leaves irresistible.
  • Trim bottom leaves, and stake plants to keep foliage off the soil.
Once you have blight, or other fungus such as powdery mildew, you will want to try and prevent it from spreading to the rest of the plant, and to your other plants in the garden. Many people use milk in a 1:9 ratio with water and spray it on the leaves of the plants every 7 to 10 days to get fungus under control. We do not drink much milk in our house and I wouldn't want to buy some just to have it go to waste.


I took Farmer Bill's advice and picked up some liquid copper concentrate. This product does not have an OMRI logo which gave me pause, but Bill assured me, copper is suitable for organic gardening. I verified that when I got home. I like the idea of copper as a nutritionist, because I know it as an anti fungal, and anti bacterial for humans too. Copper knobs and ducting in hospitals have been shown to reduce the spread of bacterial infections such as MRSA. As always when spraying something in the garden, I waited until it cooled in the evening, and made sure there were no beneficial insects present before spraying. I applied it to all of the plants that are susceptible last night and will continue to treat them every 7-10 days to help kill new spores before they can spread.

I am also going to use some corn meal on the soil as it is known to attract beneficial fungus while eliminating the kind that destroys your plants. A cornmeal milk can also be used to spray on the leaves. You can soak a cup of cornmeal in 1 gallon of water overnight, and then strain the liquid to use to spray.

With so many issues, Gidget is not convinced we are qualified to manage her garden.

2 comments:

  1. Fungal disease is one of the worst garden problems! I've spent a lot of time learning about early and late blight in the past couple of years, because late blight especially has spread across the eastern part of the U.S. in 2009 and 2010. And since it's airborne, it's impossible to completely keep it out of the garden! And then of course there are the soilborne funguses that spread from the bottom up, though I've had good results in preventing it by using thick layers of mulch to keep the spores from splashing up onto the lower leaves. Still...even with preventive measures, I always know that I'll be battling fungus in one form or another. I've used a very good copper spray called Soap Shield (from Gardens Alive), but because of our bees, I'm trying to stay completely away from anything that's not completely natural. Yikes! It's very difficult, but I am going to use the Cornell Formula, and hopefully I'll have good success with it. I used another natural remedy from Gardens Alive last year, but I've forgotten the name of it. I'll check it out and will post it here, just in case anyone wants to try it. Gardening is SO challenging, especially in this weather. Gidget does look a little worried, but I'm sure she knows that her garden is in very capable hands, Crystal, with you and Farmer D on the job!

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  2. OMG.. I didnt sign up for this nightmare.. I'm already feeling defeated! Maybe I'll donate my seedlings......

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