I’m beginning to see the stirrings of life on some plants and although I’m enjoying some down time after the holidays there are several tasks that it’s time to do. If we lived where the snow drifts were 10 feet high, we could procrastinate a while but here in California, the game is afoot.
My first priority is to prune the roses before they start leafing out which wastes plant energy. I want them to produce lots of roses not just a few exhibition size so I prune shrubs moderately. Remember your goal is to keep the center of the plant open for good air circulation. Aim for a vase-shaped bush with an open center by cutting out crossing canes, spindly, weak, broken or diseased stems as well as dead wood. Cut back the remaining stems by about one-third, cutting canes at a 45-degree angle, just above an outward facing bud. Don’t worry whether you’re pruning job is perfect. Roses are super forgiving and you can trim them up again later. I once helped prune the rose garden at historic Gamble Gardens in Palo Alto. To revitalize the old shrubs we sawed out most of the beefy canes. I didn’t think they could recover in time for the big May bloom but they did and were spectacular. Roses are like redwoods,-you can’t kill one-they’re the energizer bunnies of the plant world.
Climbing roses require little pruning. Cut out extra stems if there are too many and also cut back long established canes to about the place where they are slightly thicker than a pencil. Then cut each side stem down to several inches. This will cause the cane to flower along its complete length for a beautiful spring display.
Remove any leaves that may still be clinging to the bush. Rake up debris beneath the plant and discard to eliminate overwintering fungus spores. It’s a good idea to spray the bare plant and the surrounding soil with a combination organic horticultural oil to smother overwintering insect eggs and a dormant spray like lime-sulfur to kill fungus spores. If you usually only have problems with black spot you can use a mixture of 1 teaspoon baking soda with a few drops of light oil in 1 quart water and spraying every 7 to 10 days.
Other tasks to do in the garden in January:
–Cut back hydrangeas if you haven’t already done so. Apply soil sulfur, aluminum sulfate or other acidifier if you want to encourage blue flowers.
–Prune fruit, nut and shade trees and spray with horticultural oil and lime sulfur or copper dormant spray. Don’t use lime-sulfer on apricots, though.
–Cut back summer flowering deciduous shrubs and vines. Don’t prune spring flowering varieties like lilac, flowering cherry, plum and crabapple, rhododendrons, azaleas, camellias, weigela and spirea until after flowering or you can cut some during flowering to bring in cuttings for bouquets.
– honeysuckle, potato vine, morning glory, trumpet creeper and pink jasmine by thinning now or even cutting back low to the ground if they are a big tangled mess.