Hi Tadzio

Welcome to GW Roses and we're glad to help with advice. There are two kinds of things that you can do to promote more blooming from a climbing rose. The most immediate help you can give is to gradually encourage that one cane to bend horizontally against whatever is supporting it, so that the cane will start to send out what are called "laterals". Those are the primary blooming canes of a climber. If you let a climber grow on its own, it will only bloom at the highest point and that's what you're seeing now. By bending the cane horizontally, all those laterals will be able to bloom at their highest points and it then gives the impact of more blooms all along the length. I wouldn't cut back the primary cane, since you want that base to start from to promote growth of the laterals.

If the canes are flexible enough, it's possible to gradually encourage the canes to do a gentle zigzag pattern against the support so that the main cane can keep getting longer but still relatively contained against your support. Remember that roses won't attach themselves to the supports on their own, so you need to use something to attach it to the support, since you've discovered that on its own it wants to grow straight up. There are green velcro type ties sold at garden or hardware stores, or things like cut panty hose can work well. I wouldn't use hard supports like zip ties or clamps since they can damage the canes and are hard to readjust as the climber grows.

I say gradually encourage in all these things, because the cane gets stiffer the older it gets and more reluctant to bend the way you want it. You might need to encourage it to bend to say 30 degrees, then 45 degrees after a few weeks, then work toward horizontal over time. Pulling the canes below horizontal isn't the best idea since the canes that point toward the ground are likely to die off up to the horizontal point - something about circulation as I understand it. You can keep bending the laterals horizontally toward the sides - spreading them out into a fan shape is a nice pattern for a climbing rose - and those laterals will put out laterals, etc.

The second strategy can be to encourage the rose to grow more canes from the base, called basal canes. Climbers aren't as likely to get bushy with lots of canes from the base as other roses, but they can do this over time, and some are better than others. I get some results from spreading alfalfa hay around the base of the rose and working into the mulch, as alfalfa encourages basal breaks. Others have recommended mounding soil around the base of the rose to do the same, but I haven't tried that. It's more of a long-term strategy.

One other point - if your climber is dark red with long thin canes and only blooms once in the year (May-June in most regions) you're likely to have a rootstock rose blooming rather than the original one planted. It's Dr. Huey, and most of us that are into roses dig him up because there are better climbers out there and he's pretty hard to dig out once he's there. It's your choice what to do about it if so, and Dr. Huey stays floppy and pretty prone to leaf diseases like blackspot regardless of what you'd do.

FWIW, it usually helps us help you if you let us know your general region of the country, since rose advice varies by regions and coldness zones.
Hope this helps

Cynthia

Thanks so much! I am in zone 7, and the climber is an all-summer bloomer (I have a nice canopy of white flowers the whole year, and I could see them if I were a giant). I worry the canes I have now (basically one cane for each of two roses) are too thick to re-train. I will try the alfalfa approach. If I get some new canes, can/should I prune away the large one to promote growth of the newer ones?

I’m curious if it’s ok to hack the main canes down to 1-2ft, then try to horizontally train new growth as it emerges.

Yes, that's a good question!

hello =),

T K do you have a picture of the roses in question so we can better see what you are working with? I also would consider cutting it down to about 2-3' and starting over.