Pruning for Good Health

by Dick Streeper

WE ALL KNOW that good health is founded upon a fluid knowledge of nature. Man, and also woman, is the husband of the roses grown in our garden. Roses depend upon us to tend to their well being. Winter is the time, and winter-pruning is the activity, which most critically affects the health of roses. It is easy to learn the basics of the art of winter pruning and that I will disclose in the next few minutes as you read.

In order to know how to prune a rose, one must know a few basics of rose physiology. Most roses are budded onto rootstock. A budded plant combines a proven variety for production of a root system combined with a top growth of a flowering variety of superior vigor and blooming qualities. The point at which the flowering variety is budded to the rootstock is called the budhead or bud-union. In San Diego, the point should be located slightly above the soil level. Each winter, the soil should be removed to about half an inch below te budhead. In the course of the growing season it can be buried beneath mulch which should be applied to the bed.

The primary purpose of winter pruning is to force the plant to renew its primary growth through the creation of new basal cases from the budhead each year in later part of spring to early summer. Go back and reread the last sentence and don't forget it. Every word is important. We are not looking for basal breaks in February or March or in September or October. They will not help to build a strong plant because early growth will not be big and strong and late growth will not mature into the hard wood which will support strong growth in the following year.

In our quick pass through rose physiology we must recognize that there are three fundamentally different forms of plant growth which require three fundamentally different approaches to pruning. The first form is an upright modern bush which would include all hybrid teas and most grandifloras, a few roses called floribundas which grow like hybrid teas, and some David Austin English Roses. The second form includes those roses which bloom in clusters or sprays and this includes a few grandifloras, nearly all floribundas and miniature roses and many old garden roses. The third form are roses which might be classified as climbers. They produce very long canes which sometimes end with a sparse number of blooms, and sometimes end with no blooms at all. However, the hormones are not wasted because they are sent to lateral shoots and in the best of cases, a great multitude of side shoots and blooms are produced. If you think about it for a minute, if you confuse one form for another and misprune, the results can be quite unfortunate,

Efficiency. That is something we should all try to achieve when we attack a rose in winter. Don't get bogged down with the small canes. If I am attacking a sparse bush Twill start at the bottom of the plant. 1ff am attacking a big bush, I will cut away everything above three feet and strip away all leaves at the start. I want to be able to clearly see the cane structure so that I can determine which canes should stay and which should go and where they should be cut.

Which canes should stay and which should go? On modern bushes such as hybrid teas we want to encourage the plant to produce two to four new vigorous canes from, or within four inches above, the budhead each year. Canes which are more than two years old should be removed to the budhead by a saw or loppers, leaving no dead stumps. As to some varieties, this is easy to do in the hands of an expert. There are many varieties which confound the most expert pruner and in those cases, we coax them along by applying our cumulative wisdom and experience. We get new canes from the budhead by limiting the number of growth buds on the plant remaining after winter pruning. Remember that there is a collection of growth buds on every cane at every point at which a leaf is attached. If the cane is cut slightly above that point, all of the hormone energy of the plant will be directed to this collection of growth buds and new growth will be concentrated at that point. In addition, similar, or slightly diminished growth will originate from the two, or sometimes three, growth buds lower on the cane.

If you have a very strong growing hybrid tea and want it to bloom at four to seven feet in the course of the year, winter prune to about three feet. If you want a smaller plant on a vigorous hybrid tea, cut it to about two feet in the winter. There are some varieties of hybrid teas which resent hard pruning and show their pique by growing backwards. Peace and many or its progeny are in the class. However, most of the newly introduced hybrid teas exhibit a common quality of vigor of growth. If it can be done without shortening the growth too much, it is best to retain no dog legs on hybrid teas and grandifloras at the time of winter pruning. A dog leg is a cane with lateral growth with the base cane cut at the point of lateral growth. Basal canes with dog legs usually result in weak growth in the first growth cycle after winter pruning.

The second group of cluster-flowered roses are bred and selected to produce masses of blooms on twiggy growth. They typically bloom two to three feet from the ground with the exception of miniatures, which belong in this group and bloom from one to three feet above soil level when planted in the ground. In the winter, we remove all dead wood and try to open up the plant in the center. But we retain a multitude of twiggy stems because these produce the masses of blooms which make this class so attractive. It should be said that all tree roses are pruned in a globular form in accordance with rules of this class.

The third group, climbers, must be handled very differently from the first two groups. Climbers should be trained and shaped but never hard-pruned. Contrary to the above two classes, old and twiggy wood is good. We want lots of short stemmed blooms on our climbers. I like to pull all climbing canes off of their trellises each winter. Side shoots are cut to about six inches in length. The main cane is cut little, if at all, and then rewoven on the trellis if possible or tied in a flat plane if it can't be woven.

For all types, remove the soil under the budhead to create about half an inch of clearance from the bottom of the budhead to the soil level. Cut away all dead stubs from the budhead and then lightly use a wire brush on the budhead to remove dead tissue. Take care not to damage any of the light tan living tissue. The object of winter pruning is to generate two or three major new basal breaks each year. It that happens, we can remove all canes which are older than two years.

Pruning of roses is an art and those who practice the art need to engage in the practice. That requires constantly observing, with an open mind, what others do and say, and serving as a teacher, or practitioner, for those who are interested in the art. Come to the SDRS rose pruning in the rose garden in Balboa Park on January 8 and 9 and help us to promote this art form.

This article was originally published in Rose Ramblings, Vol. LXXII No. 11, December, 1999. © 1999 San Diego Rose Society, Inc.

Keywords: Pruning, Basic