Gardening : January Is Preferred Rose-Pruning Month

Established roses require pruning every year, and January is the preferred month in Southern California for pruning rose bushes.

Although there are a number of good books on the subject, nothing takes the place of an actual demonstration. And this January there are a number of rose pruning demonstrations throughout the Southland.

To get a perspective on pruning roses--and some ideas for those unable to attend a demonstration--we visited Sherman Gardens in Corona Del Mar, one of the locations where the demonstrations will take place.

According to Brad Carter, a horticulturist at Sherman, rose pruning accomplishes several objectives: It encourages strong new growth, promotes cane production, shapes the bush for maximum landscaping effect and opens the center of the bush to facilitate air circulation and sunlight penetration. Pruning also makes it easier to apply sprays and makes the sprays more effective.

All of these lead to the main objective--an attractive plant with beautiful blooms.

Carter says the first step in pruning a rose bush is to visualize in your mind how you want the pruned bush to look when you are done. (He likes to achieve a vase shape on his own bushes.)

Next, select your pruning tools: long-handled lopping shears and sharp pruning shears. Leather gloves are a must.

The third step focuses on the canes of the plant. The canes of a rose bush are the main branches or stems that grow vertically from the crown of the plant. The smaller side branches grow off these canes.

You should plan to remove all but four to seven canes from the plant. When planning, visualize a vase shape for the finished product.

According to Carter, the canes you want to keep on the plant are the thickest, most robust canes. These are usually the younger canes and they will still have a slight green coloring on the bark. They should ideally be 1 inch in diameter, but smaller is alright. Again, keep in mind that your goal should be four to seven of the choicest canes.

Begin the actual pruning process by removing all deadwood and all weak, twiggy branches. Then remove branches that cross the center of the plant and any that come in contact with the larger canes. Remove any suckers from the base of the plant by pulling them off with a rapid, downward yank.

Next, after selecting the canes you are going to keep, cut the others off at the basal crown (at the bottom of the plant). Don’t leave any stubs when you remove the canes.

Then, with the canes that you are keeping, remove the lateral branches so that you essentially have long, thick canes with no branches on them.

You then cut these bare canes to remove 1/3 to 1/2 of last season’s growth. Carter says that you accomplish this by locating an outward-facing (away from the center of the plant) bud (eye or swelling on the cane from which new branches will emerge). Make a 45-degree cut about 1/4 inch above the bud. Be certain to always prune at a 45-degree angle so that the slanted surface keeps water from seeping into the cut.

You now have the finished product, which is basically four to seven canes surrounding the crown and having a vase shape.

Carter recommends one more step that he considers quite important. All cuts should be sealed. To do this, Carter applies a white glue (such as Elmer’s) to the cuts. A commercial sealer may also be used instead of the glue.

Carter cautions that the instructions here apply only to hybrid tea and grandiflora roses. Floribundas require a milder pruning, and climbing and old-fashioned roses are pruned differently.

If you can spare the time, attend one of the rose pruning demonstrations scheduled over the next few weeks. These demonstrations not only provide visual instructions but also give you a chance to have your questions answered.

Here is a rundown of Southland demonstrations listed in chronological order.

Jan. 6: Huntington Botanical Gardens, 1151 Oxford Road, San Marino; phone (818) 405-2141. At 1:30 and 2:30 p.m. Also Jan. 9, same times.

Jan. 7: South Coast Botanic Garden, 26300 Crenshaw Blvd., Palos Verdes Peninsula; phone (213) 772-5813. 11 a.m. to 2 p.m.

Jan. 13: Sherman Library and Gardens, 2647 E. Coast Highway, Corona Del Mar; phone (714) 673-2261. 9:30 to 11 a.m.

Jan. 13: Descanso Gardens, 1418 Descanso Drive, La Canada; phone (818) 790-5571. 1 to 4 p.m.

Jan. 13: Glendale Civic Auditorium, 1401 N. Verdugo Road, Glendale; phone (818) 956-2000. Rose pruning and garden show. 9 a.m. to 5 p.m.

Jan. 20: Fullerton Arboretum, Yorba Linda Boulevard and Associated Road, Fullerton; phone (714) 773-3579. 1 to 3 p.m.

The demonstrations listed above are free of charge; however, there is an admission charge at some of the gardens. All demonstrations are subject to cancellation in the event of rain.