March is the time to prune roses

The Daily Ardmoreite
Pat Neasbitt
Master Gardener

It is time to prune all roses now except for the once-blooming varieties such as ramblers and old garden roses that need to be pruned immediately after they bloom. There are several pruning processes that are common to all roses whether it is a hybrid tea, floribunda, miniature, or shrub rose. Before you begin, get a good pair of rose pruning gloves that cover your arms as well as your hands and provide protection from thorns.

• First is the angle of the cut. Always cut stems at a 45-degree angle, making the cut about one quarter inch above an outward facing bud. The outward facing bud will direct growth away from the center of the plant to allow more light and air into the center. The cut should always slant away from the bud, not toward it so water will drain away from the bud.

• When you prune roses, always remove the four D’s - dead, diseased, damaged, and dinky wood. Cut down to the bud union when removing an entire branch. It is an enlarged area at ground level where the canes start growing.

• Next, remove any branches that are crossing. They will rub against each other causing open wounds that let in insects and diseases.

• Remove branches that are growing inward toward the center of the plant. Take out all stems less than the size of a pencil (dinky). You want an open, graceful plant with lots of flowers, not one with a lot of shrubby growth in the center that blocks air and light, holds moisture, and invites diseases.

• In order to get the most blooms on hybrid teas, floribundas, and miniature roses, they need to be pruned pretty severely. These roses bloom on new wood, so start by removing all dead canes to the bud union. Thin, weak canes (dinky) are removed next. Then reduce the number of remaining canes to five stout, healthy, green canes that are evenly spaced around the plant. These canes are then pruned back, leaving three to five outward facing buds. I told you it was severe!

• Shrub roses such as ‘Knockouts’ are pruned primarily to maintain size and shape. These roses bloom on mature, but not old, gray wood. Usually, no pruning is necessary during the first two or three years after a shrub rose is planted. After three seasons, use the one-third pruning method that is also best for other shrubs in the landscape. Remove one-third of the oldest canes completely to the ground every year and let one-third of the young canes that grew the previous year grow to take their place. Remove all the remaining small canes. This way the younger canes replace the old, allowing a continual renewal of the canes, and maintaining plenty of mature wood to produce an abundance of flowers. Since they are shrub roses, you can also cut back the branches quite a bit to shorten the plant if needed. I know people who use hedge trimmers on their Knockouts when they get too big, and they survive and bloom prolifically.

• The pruning process differs for climbing roses which are pruned minimally. They bloom the most when main branches are trained to grow horizontally along a fence or trellis. You can remove 1/3 of the oldest branches at ground level each year, just as with shrub roses, to keep the plant renewed. Dead wood always needs to be removed, and lateral branches coming off the main branches where the flowers are produced just need to be trimmed back if getting too long.

For more information, check out OSU Factsheet HLA-6403 Roses in Oklahoma. Stay Safe & Happy Gardening!