EFECTIVE ROSE PRUNING FOR SOUTHERN CALIFORNIA
Why Prune Roses?
Our garden roses evolved to require a period of winter dormancy. Here in the warmer costal region and inland valleys of Southern California we do not receive enough hours of cold to force our roses into dormancy naturally. So it is necessary to prune our roses and strip off any remaining foliage to encourage these shrubs to take a short winter nap. At the same time this pruning allows gardeners to take a look at how their roses have grown over the season and make some judicious cuts to help shape and direct new growth so that the shrubs fit into our gardens. In essence we are making them better garden citizens.
When to Prune?
In the milder regions of Southern California, the warm coastal zones and the mild inland valleys, roses are best pruned between the first part of January through February. Starting earlier may subject tender new growth to early frosts and the roses can suffer. Pruning should be finished by mid- to late-February. Once the soil begins to warm up to around 50° the bushes will begin to sprout new growth and should be in full flower by mid-April.
How much to prune?
Here at The Huntington Rose Garden we traditionally prune somewhat lighter than many other gardens in the region. This is because we do not prune to control the size of the bushes; they will grow back to their predetermined size no matter what at the expense of flower production. We prune to maximize bloom and shape the bushes to fit into the garden and encourage new growth which will produce better flowers.
Our garden roses are pruned to no more that one-third to one-half of what grew in the past season. A rose that has reached six feet in height would only be pruned back to between four or three feet. If a bush consistently grows to a size too large for the site simply pruning it back hard will not make it fit the site. It would is far better to move the shrub and plant another in its place that will be the right size for the garden.
Generally a hard prune, something like more than one-half, will produce somewhat larger but fewer flowers. A moderate pruning, as recommended, will produce slightly smaller but more flowers. It has been our experience that this pruning technique provides the garden with more blooms and earlier than hard pruning.
What tools will I need?
First invest in a good pair of secateurs, or scissor action hand pruners. Avoid bar and anvil types as they will crush delicate stems causing future problems. You will need gloves and garden appropriate shoes to protect your hands and feet from rose prickles. A handsaw and or a pair of loppers will allow you to make larger cuts than you can efficiently with your hand pruners. A small sharpening stone to keep your pruners sharp and a small hand rake will come in handy. Secateurs come in all price ranges and brands. Any will do as long as they cut with a scissor action and you keep them sharp and clean.
Think of your final product as looking like an open vase, with the canes radiating out in an open pattern with little growth left in the middle of the bush. Begin pruning by removing any dead or diseased canes or branches. Next remove any branches that cross through the center of the bush or rub up against another. Rubbing can cause wounds that can spread disease and eventually kill the bush. It is a good idea to remove one old cane, any cane three years or older, for each new cane produced by the bush. This helps rejuvenate the shrub and maximize flower production. Next shorten back all remaining growth to approximately one-third to one-half of what remains. Cuts should be made just above an outward facing bud eye to direct new growth away from the center of the bush. Bud eyes can be found just above a leaf joint with the stem and is the only point where new growth and flowers are produced. Finally remove any remaining leaves. This helps the bush to go completely dormant and also helps limit the spread of disease.
Many gardeners use some type of sealant compound to protect open cuts on canes larger than a pencil. This is to prevent a common insect from laying her eggs on the open wounds, the resulting larva causing damage and eventual death of the infested canes. The commonly available tar-based products often recommended can cause more dieback and problems and for this reason are not recommended for use on roses. There are several products that are not tar-based and would be fine. If you don't have these handy then sealing the open cuts with white glue will be just fine. Here in Southern California we find that these cane borers are not active during our pruning season and the canes heal naturally before the insect is active negating the need for sealing canes.
Finally clean up any debris remaining in the garden buy raking out any remaining leaves and flower petals. Many gardeners then choose to use a dormant spray after finishing. Dormant sprays come in several formulas so it is best to check with your local garden nursery for their recommendation of the best product to use in your area. Fertilizing roses should wait until the new growth is at least three inches, which should happen around mid- to late-March.
For pruning Climbing roses please click here.
For pruning Old Roses please click here.
ENJOY THE ROSES!