Do you have some roses that you would like to have survive the
upcoming winter, if at all possible? Or, are you one of those
who had roses going into last winter, only to have many die while
those of your neighbor lived? If either of these fits, you
might consider mulching and mounding this fall.
A mulch will not only keep the soil warmer than un-mulched soil,
but will also prevent rapid fluctuations in soil temperatures which
lead to soil heaving. Snow is the best mulch, but as we know,
can not always be counted on. So other materials must be used.
A good mulch will settle lightly on the soil surface without
excessive packing (this rules out most oak leaves), cause no harmful
effects (such as from diseases or weed seeds), and be reasonably
attractive and priced. Mulches derived from plants will also
add organic matter to the soil. Examples of good organic mulches
are peat moss, leaf mold,
weed-free straw (not hay, which is often weedy),
cut evergreen branches, bark mulch, or wood chips.
Mulches should be piled at least a foot deep around plants, and
not before mid-November, as roses need cool fall temperatures to
develop some winter hardiness. Mulch much later and you may
have to contend with snow first, and valuable ground heat will have
Mounding may also be used to protect roses during winter, simply
mounding loose soil a foot or more high around the base of the plant.
Use loose sandy or loamy soil, as dense clay soil may cut off the
oxygen supply to the roots, resulting in injured or dead plants.
Soil mounding is preferable over mulches if you have mice that may
live in organic material and chew on the rose stems.
Climbing roses may be protected by removing the canes from their
supports (keep this in mind in the spring when tying them up, for
easy fall removal), then laying them on the ground. Use a
wire hoop or similar device to hold them in place. Lay a piece
of burlap over the canes to protect them during the spring uncovering
operation, then mound soil over the canes. Uncover the canes
when they begin to grow in spring, checking them in early April
or shortly after the snow melts.
Mulching or mounding protects roses in a couple of ways.
Roses vary greatly in their hardiness, depending on species and
cultivars, with the more hardy not even needing protection.
Most roses also are grafted onto a hardier wild rose understock.
This "graft union" is the swollen area you can find at the base
of many rose plants. It is often tender and susceptible to
winter injury, so needs protection. Many recommend to even
bury this graft union below the surface when planting, which will
also help prevent undesirable sucker canes arising from the wild
Before mulching or mounding roses in mid to late November, finish
fall cleanup. Remove all plant debris and diseased parts.
Pruning, although usually done in spring, may be done now to remove
diseased or dead stems and to make the plant easier to mulch. Even with
protection, canes may have some dieback and need further
pruning in the spring. Prune then after leaves come out.
Waiting until then you'll know which stems and parts are truly winter-killed.
Dr. Leonard Perry, Extension Professor