Rose Pruning Time at Hand

(This article first appeared in the February 1989 issue of the Austin Gardener. It is based on excerpts from an article by Kathy Noble of the Austin Rose Society.)

One of the rites of spring is that ritual known as rose pruning. Even the newest rosarian knows that you are supposed to cut the roses back - but when, why, where, and how?

WHEN depends on your environment. Removing a significant amount of the rose plant stimulates a reaction - new growth. If the weather is hostile to tender, new plant tissues, it is too early to prune. Therefore, you wait until the danger of frost has passed. In Austin, the “right time” for spring pruning is usually mid-February. This is easy to remember if you associate the event with Valentine’s Day.

WHY prune the roses at all? Rose bushes have grown for hundreds of years without such care. The answer is “quality of life”, not “requirement for survival”. An unpruned bush accumulates dead plant material that fosters further decay. The tangle of stems and foliage becomes a haven for insects and fungal disease. Worst of all, new growth primarily occurs at the tips of stems (this is called apical dominance), and each generation of stem-on-stem growth is smaller and weaker than the one before. This results in small blooms of inferior quality.

Therefore, the purpose of spring pruning is to improve the following plant characteristics:

• Health - by removing dead, damaged, and diseased plant material.
• Vigor - by removing twiggy growth, i.e., stems too small to produce and support a decent bloom. Structure - by giving the plant an uncluttered structure, free from rubbing canes and dense masses of foliage.
• Size- by trimming the plant to fit into a landscape scheme. It is important to make a clean cut with a sharp blade.

Crushed stems (damaged plant cells) will decay, and ‘dieback’ will travel down a stem all the way to the bud union if left unchecked. Bypass, or scissors type pruning shears make the cleanest cut. Anvil type shears are guaranteed to crush if not razor sharp.

If you aren’t picky about the height for landscape reasons, plan to remove 1/2 to 2/3 of the bush height. You can take 1/2 off the top for starters. If the plant is a real jungle, start on one side and make a sweep across, removing everything smaller in diameter than a pencil and all deadwood (brown stubs) encountered. If you can’t leave 3 or more bud eyes on a stem, remove it entirely. This goes for canes, too. Now, if you have canes that are very close to each other, either crossing or growing parallel, pick the stronger and newer of the two, and cut the other back to where it doesn’t interfere.

Seal all cuts on wood bigger than a pencil with Elmer’s glue, cheap fingernail polish, or pruning paint. Everybody has their favorite, and swears that it is the only thing to use.

All modern roses (Hybrid Teas, Grandifloras, Floribundas, and Miniatures) can be pruned by the approach described above. The miniatures obviously require better eyesight, but the pruning is usually not so critical.

Old Garden Roses and shrub roses are another story altogether. Many have only a spring bloom, which is produced on last year’s growth. Do not prune them (except to remove dead or diseased material) until after they bloom. Then shape the plant as required. Most of the older roses look best when allowed to develop their natural form.