10 Principles of Rose Pruning

10 Principles of Rose Pruning

By Robert B. Martin, Jr.

Master Rosarian

Pruning time normally sends rose growers back to their books and out to pruning demonstrations and lectures to refresh memories on the principles of pruning. There one encounters numerous instructions on proper rose pruning techniques, some of which are altogether contradictory. Armed with or perhaps simply confused by this knowledge, many then repair to the rose garden to stumble through the process.

In an effort to bring some order to this confusion here are ten simple principles that provide guidance on pruning the large roses--Hybrid Teas and Grandifloras. With some modification, mentioned at the close, the principles also apply to pruning Floribundas and Miniatures. Climbers, Shrubs, and Old Garden Roses are another story altogether and are not addressed in this article.

As with any project, the place to start is with a plan. Thus the first rule is:

1. Plan Your Pruning From the Ground Up.

Most rose growers start the pruning process from the top, standing over their roses and nibbling away with pruning shears as if they were barbers giving their roses a trim. This wastes valuable time; it can also be damaging. The purpose of pruning is to select the strong, healthy canes that will support the new year's growth. The stuff at the top is last year's history. Get down on your knees (sit down if it's more comfortable) and look at the bud union and the canes that come from it. Think about new growth and turn to rule number.

2. If It's Too Old To Cut It, Cut It.

Identify the newest canes. They are the ones that are the greenest. Then identify any older canes. (If your bush is young--say two to three years old--you may not have much in the way of older canes.) Like people, they are the ones that are craggy and gray. This is not the time for nostalgia. The old gray ones usually have weak spindly growth on them and are in the way of brand new canes that are now only a gleam in the bud union's dormant eyes. Use your loppers or handy pruning saw and cut the old buzzards off flush with the bud union. When this is accomplished, turn to rule number 3:

3. If It's In the Way, Cut It Away.

New growth needs room and the ideal plant grows out from the center. Identify any canes that cross directly over the center and cut them off with your loppers or pruning saw flush with the bud union or, as is more generally the case, flush with the cane from which they have decided to grow in the wrong direction. Also, identify any canes that are seriously crowding each other. If they are not too close you can wedge them apart with a piece of stem cut from the plant. If not, cut them out with your loppers or pruning saw, again flush with the bud union or the cane from which they are growing. The remaining canes are now your bush and are ready to be pruned back--leading to the next rule:

4. The Height Is As Simple As 1-2-3.

The relative merits of severe versus light rose pruning are debated at length in the rose literature. Most proponents of severe pruning are from areas that require winter protection for their roses. Since the cold is going to kill back long rose canes anyway this makes sense. The proponents of very light pruning either don't know what they are doing, are too faint-hearted, or have an inordinate love of bushy foliage and small blooms on short stems. In my Southern California climate, neither approach makes sense. Mentally divide the cane into three equal parts and prepare to remove the top one-third. Before you do, however, proceed to rule number 5:

5. For All You Do, This Bud's For You.

If you are unusually lucky, exactly 2/3rds of the way up the rose cane (or 1/3rd down depending on whether you have now stood up) will be an outward facing bud eye. Bud eyes are found at the intersection of the cane and a leaflet of five. They will also develop from what looks like an expanded band on the cane. Sometimes they are obvious; other times less so. There should be several and the generally preferred one faces out. But it is not necessary to be slavish to the outside eye rule. (Where the canes come out at a 45 degree or greater angle, a cut to the outside facing eye can often result in a horizontally spreading rose bush with canes that fall of their own weight. This is particularly true of rose bushes that tend to naturally grow horizontally. A cut to an inner facing eye in such cases will usually produce a cane that goes straight up, the best way for roses to grow.) What if there are no properly placed bud eyes? Find one and work with what you've got. If you haven't got any, double check your eyesight and if there are really no eyes of promise conclude that God didn't intend the cane to live anyway. This brings us to a very important and seemingly heartless rule:

6. When In Doubt, Cut It Out.

Many rose growers are somewhat squeamish about pruning roses, for fear they will harm a plant that produces such beautiful and delicate rose blooms. Don't let the blooms fool you--a rose bush is one tough cookie. How else could the rose have survived without the loving care of rosarians for hundreds of millions of years? The rose bush will take care of itself, so if you're puzzling about whether to leave that little stem that, although unpromising, might do something--cut it off. In this vein, we come to rule number 7:

7. If It Isn't Big Enough to Seal, It Doesn't Belong There.

Most instructional pieces on rose pruning advise you to seal cuts on stems larger than a pencil. Why, you may ask, should you consider leaving stems smaller than a pencil? A stem growing from another cane will never be larger than its source. Pencil-thick rose stems produce matchstick-thick stems that produce pin-thick stems that produce roses that only the thick-headed could love. Forget also the common instructions about sealing with shellac (who can find shellac anymore?) or nail polish or God forbid, the black, oily spray-on sealing goop that invariably gets sprayed on the bud eye, forever sealing it from growth. A drop of Elmer's or any white glue is fast and easy. Ignore those who claim you needn't seal in the winter because the cane borers are not active. This may be true where it's below freezing and the borers are all dead, but having personally lost more canes to borers than I care to disclose, I can guarantee you that if there is one borer in your neighborhood that is still alive, it'll drill a hole right into the end of your cane and deposit a creature that, if disregarded, will eat its way all the way to the bud union. Don't give the sucker an even break. And while we're talking about giving bugs a break, consider the next rule:

8. Leave No Leaves.

Strip all the remaining leaves on the rose bush. They too are last year's history. You want new leaves that can get a good start without catching fungus infections or facing attack from the bugs hanging around the old leaves. After this, your rosebush should be looking pretty bare and you can wrap up your work with a little advice that sounds like it came from Mom:

9. Don't Forget To Brush!

Take a wire brush and brush off that scaly woody stuff on the bud union at the base of the rose bush. Try not to brush off any promising bud eyes while you're at it. Rose lore says this exercise will stimulate and provide room for basal breaks--new canes from the bud union. Whether this is really true has not exactly been proven, but it seems like a good idea and maybe the bush you just butchered will consider it a pat on the head and recognize that you still love it. But before you get too dreamy, you can turn to the last rule, which coincidentally also sounds like a word from Mom:

10. Clean Up After Yourself.

Gather up all the canes, stems, leaves and miscellaneous stuff you've generated, bag it up and throw it away. While you're at it, yank the weeds from around the bush and get rid of all the dead leaves and dried up old petals lying around. All of last year's fungus and insect problems are lying around in this stuff waiting for the new blooms. And don't bother to compost it. Rose canes don't decompose well and the spores, eggs and other things in the mess seem to survive composting efforts quite well. Finally, lay down some new mulch to make things look real neat. Your Mom will be proud of you and will love the roses that bloom in the spring, tra la.

The above rules also generally apply to floribunda roses, however the trick here is to prune more lightly and to not worry about leaving thin stems. The rules also generally work on Miniature roses; however, since they are usually growing on their own roots, you can leave a lot more canes. In both cases, careful pruning can get rather tedious so some growers simply prune off the top third of the rose bush with hedge shears like a shrub and get pretty good results.