When setting out new bare-root rose bushes, soak the plants in a bucket of 1/2 cup of epsom salt per one gallon of water for several hours or overnight to revitalize the roots. Add one tablespoon of epsom salt to each rose planting hole, mixing it with the soil.
Healthy, established rose shrubs will benefit from 1/2 cup epsom salt scratched into the surface of the soil around the plant base in the spring.
