Wednesday, February 17, 2016
Now that Valentine’s Day has come and gone, it’s time to pay attention to your roses.
On the west side of the Cascade Range, mid-February is generally time to start thinking about pruning, according to Amy Jo Detweiler, a horticulturist with Oregon State University’s Extension Service. Take your cue from the plants. When the buds begin to swell and get ready to break open, pull out your pruners.
Detweiler recommends using bypass pruners rather than anvil because they cut more like scissors and won’t crush the stems. Make sure they are sharp. Have some rubbing alcohol on hand for dipping the blades in between cuts, especially as you move from rose to rose.
As you get started, stand back and survey the rose. First cut out any dead, diseased or damaged wood (also called canes). Remove anything smaller than a pencil. Then find three to five of the healthiest canes and clip those back uniformly to 14 to 16 inches above the ground. Make your cut just above a bud that faces outward and prune at a 45-degree slant.
“You want the shrub to grow outward so that the center remains relatively open,” Detweiler said. “That increases air circulation and reduces the chances of disease.”
Be sure to clean up and remove all debris.
Detweiler’s directions specifically apply to modern roses such as hybrid teas, floribundas and grandifloras, but also pertain to old-fashioned and shrub roses, though those can be pruned taller — just a third of the plant’s size. Roses that bloom just once a year should be pruned right after blooming.
In Western Oregon, prime planting time is coming up, Detweiler said. When you go to the garden center to buy a rose, look for a plant with stems that are green and healthy. Dead branches or dieback might indicate disease. Also, make sure the roots aren’t winding around inside the pot or growing thickly out the bottom drainage holes.
Dig a generous hole, twice as wide as the pot the rose came in and as deep. Mix together one-third organic amendment such as planting compost and two-thirds native soil that came out of the hole.
Place plant in the hole and fill in with soil and compost mixture. In milder climates, make sure graft line is above ground. Water well. Mulch with 2 to 5 inches of organic mulch, such as bark chips or compost. Keep it level and even, not like a volcano.