The right way to prune your roses in Sonoma County

Now our deciduous fruit and nut trees, shrubs, and roses are dormant. Their buds are tight against the cold nights. Their sap hunkers down in the roots, and won’t rise in most of them for another month.

Now, in other words, is the time to prune.

Some overall rules for pruning include the admonition to remove all suckers arising from the roots or trunk below the graft. Most fruit and nut bearing plants are grafted onto rootstocks selected for performance as roots, not for the quality of their produce. We are surrounded here in Wine Country, for instance, with desired grapes for wine - cabernet sauvignon, zinfandel and varietals that are grafted onto rootstock that’s resistant to the phylloxera root louse, among other qualities. That’s a plus, but you probably wouldn’t want to drink wine from that rootstock’s own grapes.

If you’ve ever planted a rose and then noticed after a few years that the rose starts producing flowers of a different color or size or shape, it’s most likely that the rose has sent up suckers from its rootstock.

Also, prune to take out old wood that is thick and no longer bears many flowers or much crop. It is only cluttering up the plant. Remove crossed limbs that rub against each other in the wind, scraping away bark and rendering bare spots that can be colonized by fungus or disease organisms.

An open and airy shape and mostly newer wood is a good goal for almost all pruning.

Now let’s get more specific. It matters a great deal what type of fruit tree you have, because different kinds of trees require different pruning strategies. Here’s a quick rundown:

Stone Fruits - Prune nectarines, peaches, and apricots so that the fruits are within easy reach.

This is best achieved by pruning for an open center, without tall upright leaders. Shoots on the remaining limbs will elongate over the growing season.

Trim them back by one third now when they’re dormant. The result is a bowl-shaped tree with plenty of air space among the branches.

Prunes and cherries don’t need as much pruning, but keep them from being cluttered. Again, open and airy and fruit within reach is what you’re after.

Apples - Apples like a strong central leader, but one is enough. Prune out clutter, prune back long shoots by a third, and keep the fruit within reach. The ideal shape is a horizontal oval. Think of a football on its side.

Pears - Pears, including Asian pears, don’t require a lot of pruning, but follow the general guideline for open and airy.

Too much cutting will only encourage fire blight, a bacterial infection to which both kinds of trees are susceptible, and which can kill your trees.

Ornamental Shrubs - Flowering woody shrubs should be kept young and fresh-looking. Prune out woody stems that are at least three years or older.

Remove thick clutter and crossed stems and branches. The amount of bloom depends on how much sunlight they get, so the more the young wood is exposed to the sun, the better they’ll look.

A shrub that’s all closed in with extraneous wood and leaves is not going to flower well or look its best.

Roses - There are two kinds of roses. Once-blooming types put on an annual big show in May or June, and flower no more until next spring.

Repeat blooming roses put out several flushes of flowers over the course of the year. You must understand these types in order to prune properly.

Let’s take them one by one.

Once-blooming roses come to us mostly from ancient times, before explorers in the 17th and 18th centuries came back from China with roses that had a repeat-blooming habit.

The once-bloomers flower on last year’s wood. This means that you should prune them right after they flower. They will then develop canes over the rest of the growing season that will become next year’s flowering wood. If you prune once-bloomers now, in January, you’ll be pruning off the coming year’s flowers.

Once-bloomers include the wonderfully fragrant gallicas and damasks.

Hybrid teas are repeat-bloomers. You prune them now and you prune them hard, because they bloom on new wood.

Hybrid teas should be cut back to just three sticks no more than a foot tall, because you’re trying to stimulate the production of new wood come spring.

It’s the new wood that will produce the flowers and keep flowering all summer into the fall. Other repeat-bloomers are the grandifloras, floribundas, and shrub roses.

Prune these to a simple, open, airy shape, although you needn’t be as drastic with your pruners as you are with hybrid teas.

Finally, there is much horticulture to be learned by watching closely how plants respond to pruning.

Keep a little notebook. Try different cuts on different plants and make notes as to how the plants respond.

Record which pruning techniques give you what you want.

In a way, it’s like giving a human a haircut. Done well, it looks great. Done poorly, wear a hat.

Jeff Cox is a Kenwood-based garden and food writer who can be reached at jeffcox@sonic.net.