Question
I live in Zone 7b.
Please advise me as to what you do to mulch your roses and why.
I am only interested in organic methods.
Thank you.

Answer
Some people think we mulch Roses to keep them from getting too cold.  But there are other really good reasons to mulch.

After a mild autumn, and delayed dormancy, mulch provides a thermal layer and protects growth that is not yet hardened from a sudden freeze.

Mulch is something that goes on after the soil has chilled.  The point of mulching is to postpone new growth in the spring that would be damaged or killed by sudden severe weather.  Mulch retains moisture for your Roses, increasing odds of winter root survival.

Mulch saves Roses from painful freezing/thaws throughout the winter.  Frost heaving -- the thawing and re-freezing of soil around the roots -- is murder on roots.  A good Mulch lets air and water in and out of the soil, a thermal coat all season long, breaking down slowly, eventually enriching the soil while protecting the roots.

Rosarians use many materials, including soil, dry leaves, pine needles and grass clippings.  It can't be too heavy; it has to allow for air circulation; it must not decompose rapidly; and it must be free of weeds.

In late autumn, when evening temperatures are consistently down to 20 degrees F, bury the crown of your Rose under a foot of your mulch.  The mulch stays in place through the entire winter, until all threat of a hard frost has passed.  Then it comes off.  

This is an all-purpose system.  If you use dead leaves from Organic trees, I guess you could call that Organic mulch.