I don't know about the pith of an OGR, but with roses in general, if you leave a cane with brown pith, that cane may survive and bloom and even re-bloom, but usually not with the same energy and vigor and stamina that a white-pithed cane would. There is also the chance that the brown-pithed cane will sooner or later run out of energy and slowly start dying.

One problem those of us in Zone 6 have to face is that early spring weather often includes wide swings in temperatures and sometimes some late hard freezes after the roses have already begun their spring growth. All this is very hard on canes. After a later hard freeze some years ago, I had to do lots of pruning back to white pith to allow those roses to get back to their former energy levels. In fact, it took me two years of pruning to get the roses back to "normal"--I just couldn't believe at first that that much pruning was necessary, but by the second year I realized I needed to be a bit ruthless in cutting back to good pith. The remarkable change in some of my roses that were now growing from completely white pithed canes would almost have to be seen to be believed. The abundance of bloom and vigorous growth resulting astounded me!

Unless you get specific instructions otherwise for OGRs, I'd urge you to cut back to white pith.

Kate

Um, I am inclined to agree with Kate - I have, in the past, been horrified at the amount of stem I have had to cut away and have been less than rigorous in doing so....only to end up cutting even more away later. So yes, cut it back now when you have a whole season of growth to look forward to - it may even be that your rose is so small because there is some residual disease which weakens the health of the rose overall (although I am on shaky ground with these assumptions here - certainly someone more knowledgeable will chime in).

Thank you Kate and Campanula. Since gardening is also about experimenting, this year I will leave 2 or 3 canes with brown pith. That means I will off or cut down about 6 canes, unless someone has more specific experience with RdeR to share.

Yes, I figure she is virused. And she is not on either of the heat treated rose lists. She still does well enough for me to keep her. She is an awesome color contrast to the Sunsprite right next to her.

I seem to remember a conversation about this in the past. That specifically Rose de Rescht tends towards reasonably healthy canes with brown pith.

I did a search on brown pith and a second on RdeR and didn't see it. (Although I admit to being blind at times.) We're probably remembering the same conversation.

Brown pith in a green, one-year-old cane normally indicates serious damage. But I consider tan pith in an old cane to be normal. I am wondering whether it got cold enough in Virginia this year to hurt anything beyond soft, very young canes that started in the fall.

Tan pith in an older cane, yes, I agree.

I thought Grandmother's Rose was talking about dark brown pith, which I associate with diseased wood.

Rosefolly

I haven't cut anything this year, because I don't trust the warm weather. In past years, humm, I would say tan pith in the top half to two thirds of the two foot, one year old cane, white below that. Sometimes tan to the soil line. Tan being a good bit lighter than my compost enriched dark brown dirt. Some canes have those purplish spots I associate with black spot and I always cut them off to the soil level. Does not always correlate to the tan pith.

Sometimes those purplish spots are just sunburn. When they are disease, I think of them as being related to downy mildew rather than blackspot, though I base this on photographs and descriptions, not ever having had actual tests done.