Avoid Early Blight by Planning Ahead

Watch for signs of early blight and act quickly.

Early blight is the bane of tomato growers everywhere in the north country. You will know you have it when the lower leaves of your tomato plants wither and die early in the season. Often the upper portion of the plant seems fine and will set fruit which will ripen and are perfectly fine to eat. Other times the blight will wipe out the plant in a few weeks. 

Early blight is a fungus (or two fungi) that lives in the soil and blows in on the breeze. It is almost impossible to avoid but there are some things you can do to the lessen the impact. Planning ahead for the inevitability of early blight is the best defense.

• Rotate where you plant tomatoes so that you are not planting in an infected patch. Give the infected patch at least two years before planting tomatoes there again.
• Give your plants room to breath. Crowding plants reduces air circulation creating a humid environment that fungi love. Space plants 24 to 36 inches apart. Remove lower leaves and remove suckers that develop between the leaves and the stem. Stake up the plant for good airflow.   (see link below)
• Avoid watering the leaves, water from below, mulch around your plants so that possibly infected soil does not splash up onto the leaves. Too much mulch can cause a more humid environment so keep mulch to less than one inch deep.
• Keep your tools clean with a solution of 10% bleach to water or with rubbing alcohol of 70%, so as not to spread the blight.
  
• If you see dead or blighted leaves, remove them immediately and dispose of them in the trash not the compost heap. Heavily infected plants should be removed and disposed of. Be sure to wash your hands after touching infected leaves and plants and before touching anything else in the garden; keep tools clean as well.
• Planting tomatoes a little later than normal can help avoid infection. Plant in Mid-June.  The warmer air and soil temps of mid-June with help you plants catch up quickly.

Anti-fungal sprays can help. Be sure to use as directed and use proper protection. See link below for fungicides. 

Home remedies include a spray made of a few drops of tea tree oil in a quart of water. Spray the soil before planting and spray the plant, stem and leaves, every few weeks. This may not  prevent early blight but it can slow down the infection.

Another home spray recipe:  3 tablespoons baking soda to  gallon of water, add 2 tbsp of horticultural oil or vegetable oil and 2 drops of dish soap (the soap will help the oil mix with the water). Saturate the leaves with this mixture, top and underside.  Reapply every 2 weeks. Note that baking soda can affect other nutrients in the soil such as magnesium and calcium and can affect the absorption of iron so be careful not to over apply. 

Helpful links:
 
Recognizing early blight, resistant tomato varieties and chemical control:
https://extension.umn.edu/diseases/early-blight-tomato
Pruning and staking indeterminate tomato plants for good air circulation and healthy plants
https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=staking+tomato+branches#kpvalbx=1