Issue: December 17, 2005

Roses in NM don't need winter cover | Don't put wood ash in the garden

Roses in NM don't need winter cover


I moved here from New York last summer. I didn't think it got so cold here, but now I am worried about my roses. In New York, we had to protect our roses during the winter by mounding soil and mulch around the base of the plants. Should I have done that? I noticed that my neighbors have not protected their roses.

Betty J.


It is not necessary to provide the same level of protection for roses here as you did in New York. In the most northern areas of New Mexico (or at very high elevations) some protection may be needed. In most places where people grow roses in New Mexico, it is not necessary to mound soil and mulch around the plants.

If you have rose plants that you are especially concerned about, you can put a pile of wood chips or straw around the base of the plants. This will insulate the graft union and the region just above the graft to protect the variety. If the stems above the graft freezes, they may die and you may have only the rootstock variety survive. Unfortunately, the rootstock is usually less desirable than the grafted variety that died. However, it is usually not necessary to do this in New Mexico.

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Transplant iris in winter?


I've been burning a lot of wood because it has been so cold. I recall that you have said not to put the wood ashes in my garden. Why? I hate to waste the ashes. When I was young and lived in North Carolina, my father always put the ashes in his garden.

Mike F.
Las Cruces


It is true that you should not put your wood ashes (any other ashes for that matter) into your garden soil. The ashes are very alkaline, as is our soil. That is another way of saying the ashes and soil are salty (containing many mineral salts). Ashes tend to be very high in potassium salts.

On the East Coast, the soil is acid. Because of the much greater rainfall, many of the alkaline salts have been leached from the soil. Potassium is one of the minerals that have leached away. Adding ashes on the East Coast replaces the missing mineral and reduces the acidity of the soil there. Here in New Mexico, it does the opposite. It increases the alkalinity. If potassium is needed, use a fertilizer that acidifies, not one that increases soil alkalinity, and don't use wood ashes.

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Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email:, office: 505-865-7340, ext. 113.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!