Early Blight on Tomatoes – Some strategies that have worked for me
In July of 2006 my wife and I returned from a week long vacation and discovered that all of our
tomato plants were suffering from some disease. Needless to say, we were devastated. Mother
Nature can be such a bitch. As I always do, I got over it and went looking for some answers.
The following is a summary of my blight control program.
Early blight on San Marzano Plum Tomatoes
In the Fall I spray every bed in which I grew tomatoes with copper sulfide fungicide as well as next
year’s tomato beds.
In the early Spring I spray the same beds once again.
Two weeks after the plants go into the ground I begin spraying once a week, alternating between
copper sulfide and Oxidate (an oxidizing fungicide).
When the plants go into the ground I immediately prune off any branches or leaves touching the
ground and continue this practice throughout the growing season. In addition, I pinch out any
and all suckers on determinate tomato plants.
Regarding indeterminate tomatoes, I employ a little different strategy. First of all, I prune and train
the plants to be more two dimensional. It’s so much easier to do a thorough spraying. As with the
determinate tomatoes I prune anything that touches the ground. In addition, I only allow the main
leader and two suckers to grow (one on each side of the main leader). I use a trellis system consisting
of heavy duty steel fence posts driven into the ground. I attach horizontal bars made up of fir or cedar
1 x 4’s attached to the fence posts with nuts and bolts or bolts with cotter pins (my favorite).
I attach stainless steel screws to the 1 x 4’s every 6 inches. They are driven in part way.
I then zigzag tomato twine (available for Johnny’s Selected Seeds) top to bottom. I can then attach
the tomato plants to the twine using tomato clips. I love this system because it allows me to easily
keep track of each plant’s growth and to find and eliminate suckers as they emerge. A neater, more
well groomed tomato plant is much easier to cope with if it should get the blight. I will cut off the
diseased branches before spraying. See my earlier post “Tomatoes, the First Pruning”.
I have observed that some of my tomato plants seem to be more resistant to Early Blight than
others. This year I tried growing “Nebraska Wedding” tomatoes for the first time. They are
remarkably blight resistant. In addition, BHN-624, a hybrid cherry tomato has shown above
average blight tolerance.
One final thought:
My mindset is one of managing the problem. I expect to get Early Blight so I’m ready when