I have a handful of roses that for one reason or another have crowns that are essentially dead except for one edge that supports one or two live canes. These are all own root roses, but though the roots and the cane appear to be quite healthy, the plant is held back by the mass of dead material.
My thought was that if I could get new roots to grow from the healthy side of the crown, or even better, if I could get them to grow from the cane above the crown, I could rejuvinate the rose. I’ve thought about a couple of ways to do this.
I could try air layering, but I failed to have success with this on a previous attempt. Fortunately I was able to prune below the failed attempt and the cane survived
I could replant the rose in a deeper pot and simply cover the first two inches of cane with soil. I’m not sure if I should wound the cane and dust it with #3 rooting powder, or if this is too risky for infection
Worst case, I could try grafting the cane onto a multiflora rootstock, and then in future years bury the union below the surface to hope that basal breaks will occur from the new union.
Is there any option that I’m not considering? If not, which method do you think would be most likely to achieve best results?
Welcome to the forum Mark. Are your roses all in pots? Did you propagate them or buy them? Some roses perform poorly if not grafted. Grafting on multiflora rootstock would be a good solution. Once the rose is growing vigorously planting the graft below ground should eventually become an own root plant. What type of soil mix are you using?
There are two products I use to encourage rose root growth: Senn’s Sennsensational Seaumic it is a combo of humic and fulvic acids, sold both as a liquid and granular, and Natural Alternatives Protelizer, it comes in a small container, white powder dissolved in water.
I asked the questions to determine if there are other causes of the poor root growth. What zone are you in?
I may not have understood your question. If I did, none of the three options will help you rejuvenate this bush. The second option, namely, repotting in a larger container with a good potting soil might work. Air layering is a method for producing a new plant, a baby plant. Then you grow it into a mature plant.
Grafting the existing cane on to a rootstock is not a good option. In grafting, most of the time, a soft wood or medium hardwood Scion is used. That will also get you a new grafted plant and does not help you rejuvenate the existing two canes.
I would simply repot into a much larger container with a good potting soil, make sure the plant gets watered regularly, has adequate exposure to the sunlight, apply fertilizers judiciously, make sure the container drains properly, and hope for the best.