COMMENT: As a serious amateur rose grower since 1939, I would like to add a postscript to your answer to a question from A.W. in your July 12 column concerning winter mulch for roses. One thing to remember is that mulch is not to keep roses warm, but to keep them cold. When a thaw arrives in winter, without mulch the ground around the bush would thaw, too, and the bushes would heave out of the soil, then settle back as the ground froze again.
For winter care, my bushes are hilled up to 10 or 12 inches with clean soil. Then depressions are filled with cow manure. Rosebushes are cut back only enough to keep them from whipping in the wind.
My whole bed is then covered with a foot of salt hay (as late as possible to outsmart field mice).
In spring, the salt hay is removed first, and a few weeks later the earth is raked over the cow manure, and bushes are pruned to three to five outside ``eyes.''
I appreciate your helpful column. I can tell you are actual growers. A.E.H., Shelton, Conn.
We thank you for the kind words and for your detailed instructions for the winter protection of roses.
We are sure Northern rose growers who have cow (or horse) manure and salt hay available to them will want to use your excellent suggestions.
We should caution that they not let manure touch stems, as it can cause a chemical burn, injuring plant tissue, as did the sawdust that A.W. (July 12 column) used.
You are correct. Prevention of thawing and heaving is imperative. Also, the mulch is necessary to prevent premature cell activity and sap flow. Should cells fill with liquid without proper mulch, freezing causes ice crystals to form in cells and pierce the cell walls, thus killing the canes.
Folks who have rodent problems may want to add some rock wool to salt hay or straw to repel them.