Dallas Morning News – April 23, 2020

Disease Management in the Veggie Garden

Well, how’s your garden? Let’s cover some issues that might be popping up, especially since the weather has been so erratic and wetter than usual.

For diseases that have started to appear, such as powdery mildew on squash, zucchini and other crops there are several effective organic choices. Mildews are fungal so baking soda, potassium bicarbonate and cornmeal tea sprays are effective. All of my simple formulas for these homemade sprays and treatments are under GUIDES on the home page of dirtdoctor.com. The best commercial product is PureGro Disease Stop.

Powdery mildew starting on squash

For curly top on tomatoes, a virus that crinkles the new growth and mosaic virus that discolors squash and related crops, hydrogen peroxide is the cure. Mix the 3% stuff from the grocery store 50/50 with water or into your foliar feeding mixture.

Besides mildew, the most common disease that will annoy you and your veggies is early blight on tomatoes that starts by yellowing the lowest leaves and moves up the plant. This disease if often misidentified as spider mites. All gardeners will experience it sooner or later, but to delay it it as long as possible or maybe forever, use my recommended bed preparation, with plenty of whole ground cornmeal included. To the existing soil add 2-4″ of compost, 8 lbs. of both lava sand and Azomite per 100 sq. ft., along 5 lbs. of both dry molasses and whole ground cornmeal.

Early blight starting on tomatoes

Red spider mites – not early blight

The stimulation of Trichoderma and other beneficial soil life is what happens from this good bed prep. What will also help with both the prevention and cure of Early Blight if it flares up is spraying PureGro Disease Stop.

If spider mites really are attacking (little red dots inside a fine web) getting rid of them with any spray containing seaweed is easy and works well. Although, they will return if the actual cause isn’t corrected. Red spider mites attack plants in stress from watering either too much or too little. Really lousy soil will also cause the plant’s water movement and use to be the problem.

Whole ground cornmeal – best tool for fungal diseases

And finally, to prevent a cosmetic problem that looks like a disease, use some Epsom salt. That’s right – same stuff you add to the bath water to soak sore muscles. Mix a handful of the white material into the soil around each tomato plant. Another way I like is to mix a rounded tablespoon of it in a gallon of water and pour on and around each plant. What’s it called? It’s blossom end rot. The bottom end of the tomato turns brown and gets soft. Epsom salt is magnesium sulfate and provides those lacking nutrients to prevent the blossom end rot condition. Long term, the organic program will provide all the major, secondary and trace minerals and you’ll rarely if ever see these brown spots.