COMMENTARY

Don't let bugs bully your beans

8/9/2017
BY KELLY HEIDBREDER
GET GROWING
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  • Do you see some holes in your leaves? Bean leaf beetles might be making a meal out of your beans too.

    Read more from Kelly Heidbreder

    You might think there is enough foliage to go around, but these little beetles can do some serious damage. If your plants get infested early in the season, they might not have a big enough root system to grow through the bugs’ feast.

    Baskets of beans

    Your beans should be filling out and even giving you a few baskets full of crisp legumes by now. But if you see a few leaves with some spots and crinkles in them, your fresh side dish could be in jeopardy.

    If you see a little yellow fuzzy bug on your beans, it might be an unwelcome visitor. Mexican bean beetles look like ladybugs on steroids, and their larvae are yellow and look fuzzy. Larvae are big eats, despite their size. A huge population could damage your crop, but a few here and there won’t hurt a thing.

    Next, check for little black spots on the leaves and pods. This could be anthracnose. This fungus travels with the wind and water on your plants. You might spread it on your tools, seeds, containers or even your shoes. You might find these black, sunken ulcers on many kinds of plants, because they will affect almost anything. But beans, roses, grapes, brambles and cucurbita are very prone to anthracnose.

    If you see these spots on your plants, wait until the soil is dry, then pull the plants out. Try to keep the leaves of the neighboring plants dry so the fungus doesn’t spread. Keep the leaf debris picked up around the plants, toss all of their litter in the burn barrel, and look for disease resistant varieties to plant next year.

    Down and dirty

    Bean mosaic disease is a virus that can be found in the soil. In sick plants, new leaves will look crinkled and yellow, and they don’t produce very many pods. The best way to protect your garden from mosaic is to look for disease-resistant seeds. The virus is usually spread by tiny aphids on your plants.

    Pull infected plants out right away and try luring some predatory ladybugs to do some munching on the aphids in your patch. Since bean mosaic is spread by aphids, your chances of growing a great crop in that same spot next year are good.

    Wilty beans could also mean they have a case of fusarium wilt. This attacks the roots and causes plants to grow very slowly. Because the roots are weak, you will see the plants start to wilt on hot days. Some leaves may even turn yellow.

    Fusarium is a fungus that can affect many kinds of plants, including tomatoes, asparagus, cabbage, corn, cucumbers and watermelons. But each strain usually stays with its host. For example, the fusarium wilting your beans won’t affect the tomatoes you plant in that same spot next year.

    If your beans get a bad case of wfilt or mosaic, you may as well raise the white flag and surrender, because there is nothing you can do to stop it. Pull the affected plants out of the ground and burn them. Don’t till these plants back into the garden this fall, because you could add to the problem next summer.

    A new plan

    With these tips on plant diseases, now you have some chores to do around the garden.

    But I have another tip for you to think about: Find another spot for your beans next spring. Rotating their location helps solve some of the above problems, as soil-borne diseases can keep cropping up from season to season.

    So, once you get your beans canned, you can start mapping a new location for your crop.

    Contact Kelly Heidbreder at getgrowing@gmail.com.