Using Epsom Salts to Fertilize Roses

Q. My neighbor puts epsom salts in the soil around his rose bushes instead of fertilizer. Is there any advantage to this?

A. Epsom salts have a long tradition of being used in the garden, especially in Europe, before commercial fertilizers became readily available. They are a fast-acting source for magnesium and sulfur. For soils on the alkaline side, the added sulfur is a benefit. Epsom salts, however, do not contain any of the three major components of most fertilizers—nitrogen, phosphorus or potassium—and therefore would not be a complete fertilizer for roses. If you choose a commercial product, one with a 10-10-10 or 10-15-10 ratio, apply it first when the leaves have opened; second, after the first flush of blooms; and finally, at the end of July.