A more gradual strategy would be to take off just the worst one of the two big woody canes this year and leave the other. Then next year, after getting hopefully another new basal cane or two, take off the other big woody old cane.

Why not take out one of the old canes this year, fertilize generously,and then,hopefully, when some more new canes sprout, take out the other old cane? seems a shame to SP it; sounds like it just needs re-juvenating...

Actually, I am going to chance my arm and say go for it - off with its head. I have been quite brutal one several ocassions with New Dawn, Madame Gregoire Staechelin and yep, Mme Alfred Carriere, and chopped them to the ground (and New Dawn was done 2 years in succession). They did not die....in fact, both MAC and MGS came back stronger than ever (although ND sulked a little for a year (hardly surprising) but is making a comeback now.

Further more, it will throw new canes from the base as long as you leave enough of the stumps for a dormant bud to emerge (so obviously, don't whack them off 2 inches above the graft, leave around 6inches and use a sharp pullsaw rather than trying loppers.

The usual stuff with a spring top-dressing and a bit of care and love next season apply.

I can personally attest that you can cut off fully 1/3 to 1/2 of MAC and not faze her one bit. My approach was more like the gradual approach suggested by hoovb and bart (sawed off some major canes and left others) and not the beheading suggested by campanula (I fear that might produce a "coppicing" effect that could be hard to sort out). In all events, I would be surprised if MAC wouldn't survive, no matter what, especially with a little TLC.

Before you cut any of it, is the plant budded or own root? If it's budded, I'd think you would pretty much kill MAC but probably have a great crop of root stock. Own root might rebound eventually, but I agree that eliminating the worst, oldest cane first then the next the following year is probably better. How do they look "bad"? If it's just thick, old, bare and woody, that's normal. If it has galls on it, I'd dump the plant and take measures already discussed here on the forum. Kim

I would suggest the slow deliberate method of pruning. I pruned a 5 year old Elizabeth Taylor that had grown 10 feet tall on 2 old 1" diameter canes very aggressively. Removed one completely and cut the other down to 5 ". I now have a Dr. Huey shooting up from the roots to deal with as the ET never resprouted.