Sorry, I haven't learned how to use the Quote feature on this site yet, but there is one sentence in Kim's post that I would like to address because addressing this issue before the plant gets down to a one cane wonder can enhance the performance and longevity of the rose.
"Over time, the capillaries in that [old] cane become restricted, just as our arteries do, restricting sap flow. "
Old wood is not as efficient as new wood. You will often see a lot less foliage on these canes ... and when it gets down to one cane, this is even a bigger issue.
Without sufficient foliage, the plant cannot do its part to feed the root system through photosynthesis. Therefore, the plant is robbed of nutrients that it would naturally produce to feed itself. Along with checking the roots, when I am working to rejuvenate a plant, my goal is to get the plant to produce new wood and therefore more foliage. If a plant has been a vital and vigorous rose, pruning it down so that it will produce new wood and more foliage also gives the plant the tools to help recover. Even if there is bark covering the bud eyes on the old canes, they are there and the rose will more often than not activate them because it knows it needs foliage to survive.
If I am working on a rose that has more than one cane, I'll take one of those canes down to the bud union. No, I don't scrape the bud union as has been advised in many of the older rose books to stimulate growth. Again, the bud eyes are there and by removing the old cane, the plant is already stimulated to replace it. You end up with new wood. Of course, it depends on the rose.
Once I've started the rejuvenation process on a stressed plant, I don't allow it to put any energy into blooming. Roses have a mandate to bloom and will push growth, if possible, to generate the materials/food to enable it to bloom. I leave every leaf I can on the plant because all of them are producing food through photosynthesis. I don't care if it is blind growth or spindly growth, if it produces leaves, it stays. My goal is to help the plant to produce as much foliage as possible.
If a rose has been in place for a long time, I check to see if other plants ... trees ... have grown around it or over it so that it is getting more shade than it got when it was a thriving rose or when it was first planted.
Since I am gardening in nutrient poor soil ... it was dead soil when I started this garden ... I use very light applications of liquid fertilizers often to make the nitrogen more available to the plant sooner than it will be available while the organics are breaking down into a form that the plant can use.
As an on-going maintenance of the roses in the garden, when I am doing my spring pruning, I will remove one or two old canes to stimulate the growth of new wood. If you do this on a regular basis, you end up with roses with new wood all of the time and they can handle stress better than plants that only have old canes.
Some of this I have figured out on my own, but Kim has been my rose mentor since the beginning of my rose life and he tends to teach one how to fish instead of giving specific instructions. He teaches the "why" of things, then I have to connect the dots.
I hope this helps.
Smiles,
Lyn
