- A main cane is a cane that grows up from the base of the plant – or at least from the bottom one foot. They are vigorous, the thickest part of the rose and grow to the full height of the plant. There can be two, three and many more. Think of them as the trunks of the rose just like the trunks of a tree.
- The laterals (or side shoots) grow off the main canes. They are usually thinner, have more foliage and bear the blooms at their tips. Think of them as the branches growing off the trunks of the tree.
- This may be confusing to read but stand in front of a climbing rose, start to look at it, imagine the structure of a tree and it will become clearer. It’s a great idea to do this when the rose has dropped all its leaves like, if you live in a cold climate, now.
- The main canes are the structural, supporting, part of the climbing rose and the laterals grow off of them.
Because the main canes provide the structure is why you never prune them back. You can nip the ends by about ¼ their length but never, ever, ever hard prune down to two feet or less.
However, you can prune the laterals all you want. I generally prune them to within one to two feet of the main canes. And I’ll do this all year to keep the rose tidy. After a bloom flush is the best time.
Let’s get back to the tree analogy for a moment. Have you ever seen a tree surgeon prune a tree by cutting the trunk in half? No, they trim away at the branches but leave the main structural parts of the tree (the trunks) intact. It’s the same with climbing roses. Understanding this one essential thing about climbing roses will make it far less intimidating to stand it front yours with a pair of pruners later this winter. And one other essential thing. Wear a good thick pair of gloves when pruning climbing roses!