Pruning Roses

By Master Rosarian Barbara Ellis

Master Rosarian Barbara Ellis

An annual ritual for rosegrowers is the pruning of roses sometime from December to the end of March.  But why do the bushes need to be pruned?

For centuries they were left to their own devices and each year they bloomed. One year a rose garden was accidentally burned and that next spring the garden was full of huge rose blossoms.

For many years, the roses were burned to the ground which allowed the new growth to provide lovely flowers. Eventually the head gardener decided that there had to be a less drastic way to get those blooms without the risk of burning down the residence.

Today with grafted roses, this method would not work as well since the graft might be burned and the blooms would be from the rootstock – not what we are looking to see.

Each year roses need to go into a dormancy once the nights become cool or frosty so that the Spring is full of the expected large, full blooms.  Here in Sonoma County, it really never gets cold enough to do this naturally so we prune.  The pruning should be done late enough so that it is cool enough to stay dormant and before the nights warm.  With the warming of the weather it is getting difficult to know when to prune. And the time is getting shorter each year.

It used to be that if I had roses for the table on Thanksgiving, it was an unusual event.  This year, I cut fully open roses and buds from my bushes on December 29th.

pruning rose cuts

Correct Pruning cut.

Pruning is a process that takes time and energy but the results are definitely worth it. The first step in pruning is the major clearing out of the bush.  Most bushes are taken down 1/2 to 2/3 of their height. The dead wood is removed and the leaves are removed from the canes.

The second step is to remove all the crossing canes, cut off all small (less than the size of a pencil) canes and open the center of the bush to allow air flow. Make these cuts just above a place where a cane or bud will develop and where the cane or bud will face outwards. In our weather, it is fairly easy to determine this.

The third step is to reduce the number of canes to around 3 to 8.

Sally Holmes Rose after pruning.

Finally, any leaves that have fallen to the ground need to be picked up and the bush and surrounding ground should be sprayed with a dormant spray of copper or sulfur. Spray the surrounding ground thoroughly  as leaves that are left will allow the spores of fungi to survive the winter and infect the rosebush in the Spring when the leaves are very vulnerable. Expect to find blackspot and rust (two common rose fungi) on the leaves of your plants when you prune as the cooler Fall weather is the perfect environment for them.

The only roses that do not get this same treatment are: once blooming roses where they are pruned after they bloom (these roses bloom on the previous year’s growth), David Austin (or English roses) which do not like to be pruned as much (cut off about 1/3 and remove fewer canes) or Climbing Roses which are not cut down in size and other pruning is modified.

While it is not part of the pruning, I have always fertilized with a slow release fertilizer after spraying and cover the ground with an organic mulch. This practice keeps weeds down and eliminates the need to add fertilizer for months.

Medalion Rose after pruning.

This is, also, a time that new plants can be added to the garden.  I found that the clay of the Sonoma County soil is not good for bareroot planting as the water never drains from the hole.  My plants have mainly been potted and I can then plant throughout the year.

I moved last December and planted new roses in February.  Today they are thriving and you can see pictures of some bushes both before and after pruning. Rosebushes are not trees and canes that are cut off will be replaced by healthier and larger canes if you follow the advice of Consulting Rosarians from the Redwood Empire Rose Society.

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