Shrub Roses (Rosa spp. and cvs., Zones 3–9)
Shrub roses (basically any roses exclusive of climbers, hybrid teas, and carpet roses) can get quite large if not pruned hard every three to five years. Members of the Knock Out® series have been particularly popular with every level of gardener in recent years due to their nearly constant blooms. All shrub roses are pretty simple to prune—as long as you avoid their thorns.
When to prune: Early to mid-spring as soon you see the little red buds swell.
How to prune: I use short-handled loppers for this task. The idea is to get down deep into the plant and cut out any secondary branches bigger than your thumb. Prune back to a set of buds that run parallel to the ground (one “eye” pointing up, the other down) and at least 3 to 4 inches from the main trunk. Rub any buds off with your fingers that point toward the inside of the plant (to avoid branches forming and the creation of too dense a plant).
Sometimes these plants throw out serious water sprouts. These are branches that are greener and that drive through the plant almost straight up. Always cut these out at ground level as they occur during the growing season; their stems are weak and susceptible to insects and diseases.
You can also deadhead the spent flowers throughout the season and, while doing so, remove any branches that shoot toward the inside of the plant to maximize airflow and sunlight penetration. When a heavy frost hits, remove the rest of the flower bracts for the winter so they don’t rot and become a spot for harboring disease.
Other plants that benefit from this approach:
- Japanese spirea (Spiraea japonica* and cvs., Zones 3–8)
*See invasive alert below
*Invasive alert: Japanese spirea (Spiraea japonica)
This plant is considered invasive in GA, IN, KY, PA, and TN.
Please visit invasiveplantatlas.org for more information.
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