Posted: 17/06/2012 at 23:25
Right, ideally roses should have about six hours of light to thrive although of course some will tolerate shade better than others. But these are in the minority. Today I was in a pub garden in Twickenham (Father;s Day you see) and saw a nice white rose (perhaps 'Iceberg') in bloom but in the shade of a massive tree. The tree not only shades your old roses but deprives them of water and neutrician.
What would I do? Well for me all old roses are worth saving no matter how decrepid they are. Why not wait until October/November when they start to become dormant, then dig each one up with the largest ball of soil you can manage (OK, rose roots aren't a tightly bunched mass and most soil will fall away), and move them to another part of the garden. Reduce height to one third, water well and regularly, and feed. Take a cutting or two as well and fingers crossed, in the spring, you may well see new signs of life from the parent plant or the cuttings.