"Bert Hyman" wrote in message
...
We have two 12 year old shrub roses, supposedly "Pink Grootendorst".

One has always produced nothing but pale pink blossoms, but the other
has always had about 1/4 which are much darker, almost red.

Up 'til now I simply assumed that the grafter (these things are built
out of grafts, aren't they?) had picked up a few pieces from the
wrong pile when he built that plant, but this year I'm starting to
see a number of true bi-color blossoms, part pale pink, part dark.
Some are perfectly symmetrical, with the "north & south" quadrants
one color and the "east & west" the other.

What's up with that?

--
Bert Hyman | St. Paul, MN |

Old garden roses, miniature roses, and some
modern roses aren't grafted. They are what
is referred to as "own root". Pink Grootendorst
is a Hybrid Rugosa from 1923. I would be
tempted to assume your roses are not grafted.
You can check visually.

Several possibilities for unexpected colors:
(1) one of the rose bushes was mislabeled originally

(2) roses will sometimes throw out a different color
bloom as a natural mutation. Some varieties are
produced this way. I have a Variegata di Bologna
(Bourbon) that is supposed to be a red/white striped
rose, but which regularly produces solid reddish pink
blooms as well as the striped blooms. I recall reading
somewhere that one of this variety's parents
produced a solid bloom, so in my case the odd
colored blooms are coming from one of the parents.

(3) If your odd colored rose bush was grafted,
it could have reverted to the rootstock. But that
is probably the least likely explanation.

You might check out www.helpmefind.com and
look at the photos provided for Pink Grootendorst
to see how close the colors come to yours.

Gail
near San Antonio TX USA Zone 8