In almost every case, the red rose did not change colour — it died back to the graft over winter, and what is now growing is the rootstock it was grafted onto. The rootstock is a different, tougher rose, and its flowers are usually pink or magenta and less shapely.
Why This Matters in Colorado
Most hybrid tea and floribunda roses are grafted: a named variety joined onto a hardy root system, with a visible swollen knuckle — the graft union — near the base. Colorado is hard on that union. A dry, open winter with wild temperature swings and little snow cover can kill everything above it while the roots come through fine.
The following spring, vigorous canes come up from below the graft, the plant looks healthy, and it flowers — in the rootstock’s colour. Gardeners quite reasonably conclude their rose changed colour. It was replaced.
What Beginners Should Do
- Find the graft union — a knobbly swelling at or just below soil level. Then see where the pink canes emerge. Below the union means rootstock; above it means it really is your original rose.
- Look at the leaves. Rootstock foliage usually differs — often smaller leaflets, more of them, and a different green. Thorns tend to be different too.
- Decide honestly whether you like it. A rootstock rose is a perfectly good garden plant. It is tough, it flowers, and it asks for very little. If the pink pleases you, keep it.
- If you want the red back, replant. Once the top has died, there is no way to recover the original variety. Cutting the rootstock out will not bring it back.
- Protect the graft next winter. Mound six to eight inches of soil or compost over the union in late autumn and remove it in spring. That one step prevents most of these losses in Colorado.
- Consider own-root roses next time. They are not grafted, so anything that regrows is the variety you bought. For our winters, that is a real advantage.
Common Mistakes
- Blaming the soil. Soil pH changes hydrangea colour. It does not change rose colour.
- Feeding harder to bring the red back. There is nothing to bring back; fertiliser only feeds the rootstock.
- Planting the graft union above ground in Colorado. Advice written for milder climates. Here it should sit at or slightly below soil level.
- Leaving suckers on a rose that survived. If the named variety is still alive above the graft, canes from below will gradually outcompete it. Remove them at the source.
Related Garden Wise Resources
- Twelve July garden tips for Colorado — including feeding roses
- Fragrant daphne shrubs for Colorado gardens
- Native plants and nativars for Colorado gardens
Still have a gardening question?
Keith answers Colorado gardening questions on the radio show and online. Tell him what you are growing, where in Colorado you are growing it, and what is going wrong.
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