I have several Knockout roses that have over taken my walkway. How much can I cut them back and when should I do it?
The Gardener’s Answer
Hello, June: Knockout roses are considered low-maintenance and disease-resistant. When they are planted in favorable conditions, which yours seem to be, they can grow to be 3 to 5 feet tall and wide. This does not mean they cannot be pruned yearly to keep them a smaller size and prevent them from invading your walkway. The best time to prune your roses is late winter/early spring before new growth begins. Pruning while they are dormant will make them less susceptible to winter injury and other potential problems. As a general rule, it is best not to remove more than one-third of the size of the rose each year. If you need to remove more than this to keep them off your walkway, do so during consecutive years. Prune year after year to maintain the size you want. When it is time to cut them back, put on a thick pair of gloves and use a clean, sharp, and rust-free pair of pruners. Make your cuts flush to the nearest intersecting branch so there are no stubs. Remove all crossing canes and dead wood anytime of the year.