Overgrown Climbing Rose

Arching the bare upper canes horizontally across the support frame, the entire lower and middle section will fill out better. If she can make them point downwards (say 45⁰) that's even better. Unfortunately this is best done in late winter or early spring (Jan–Mar) while dormant.

Encourage new basal shoots by removing 1 or 2 of the oldest, woodiest stems down near the base in late winter.

This acts as a biological "reset button," forcing the rose to push energy into new base shoots.

​Expose the graft union to sunlight by clearing away heavy weeds mulch or groundcover around the base of the plant. Sunlight hitting the graft triggers dormant buds underneath the bark to wake up.

​Apply a high-nitrogen or balanced organic rose fertilizer (like alfalfa meal or dedicated rose food) in early spring, followed by deep watering.

​Once a new basal shoot reaches 18–24 inches long, begin arching and tying it horizontally while it is still soft and pliable.

Not sure a lot can be done immediately. Maybe someone else has ideas?

Talk to the new tenant and explain that the rose needs a hard prune in the winter and ask to come back then to do it.

I always prune my roses during the late Autumn .
But I often want to propagate some new roses so they often get a trim in August .
I don't think that it does them any harm .
You'll find if you give this climber a gentle prune-it will throw out shoots from lower down .

Last year we moved house. Our new home had an overgrown garden, including three rampant climbing roses.

In early October last year I got a man in to raze the garden to the ground, including cutting the climbing roses to the ground but leaving one or two stems at about 3 foot.

The roses have done very well this summer and i have tied and woven the roses into the wall trellis I put up over the winter. No bare stems, all leafy and green.

I cut a rambling rose back last year because the whole stem moved with the wind. Growth really rampant and it has flowered. But it has been covered in mildew which it never has been before