How to Control Mosaic on Bean Plants


A warm-season vegetable, beans are prized in the garden because of their easy care and abundant production. Beans are susceptible to mosaic virus, which is often spread to the plants via the aphid insect. Mosaic infections can lead to a substantially reduced crop or even kill the plant off entirely. The two types of bean mosaic, bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCNMV), cannot be eradicated once a plant is infected. You can control the mosaic viruses to prevent them from spreading to other bean plants, though.

Step 1

Purchase disease-free seed from a reputable garden center or seed supplier. Check the seed package and purchase types that are listed as resistant to BCMV and BCNMV. Heirloom seeds are less likely to be resistant, so plant these nonresistant varieties only if you haven't had mosaic problems in your garden in the past.

Step 2

Rotate the bean crop each year and avoid planting beans in the same place for at least three years. This prevent plants from becoming infected with mosaic virus organisms living in the soil. Rotating the crop is especially vital if you have had a mosaic infection in the past.

Step 3

Check the underside of leaves regularly for signs of aphid infestation. Aphids are small green, white, yellow or brown insects that live and feed in colonies on the leaves. Treat infestations immediately by rinsing the plants with an insecticidal soap daily until the infestation is gone.

Step 4

Dig up and destroy any plants infected with mosaic as soon as they are noticed to control the spread to nearby healthy plants. Symptoms include light green or yellow mosaic patterns on the leaves, stunted growth and premature plant die-back.

Tips and Warnings

  • Mosaic virus may also lead to black root rot. This causes the roots of the bean plants to turn black and wither, eventually killing the plant. Harvest bean pods only when the plants are dry and use only sterilized tools in the garden. This prevents the spread of mosaic and other diseases.

Things You'll Need

  • Disease-resistant seed
  • Insecticidal soap
  • Spade


  • Michigan State University Extension: Bean Common Mosaic Virus
Keywords: bean mosaic virus, controlling mosaic, preventing bean disease

About this Author

Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications, including the "Dollar Stretcher." Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.