The year has just begun and pruning time is nearly over, but since we receive a late frost we actually have until the end of February. The main reason we prune is to reset a rose bush’s biological clock – a wake up call to begin a new life cycle like restarting a factory.
To do the job right, one needs to have pruners of different sizes handy. Each size has a limit to the diameter thickness for which it is most efficiently used. Using too small a pruner on too large a cane can damage both. At minimum, have a pair of loppers and a standard-size pair of hand pruners. If you have some older plants with large canes that may need to be removed, a saw is a handy tool to have.
All pruners should be kept clean, sharp, and in good repair. Rubbing alcohol is ideal for cleaning pruners before and during the job. It also helps prevent transmitting diseases from plant to plant, and you can use it as first aid for punctures and scratches to your skin. A good pair of leather gloves is necessary. Those with long sleeves are good to protect our arms.
Before starting the job, lubricate the moving parts of the pruners with a little light oil (such as 3-in-1 or WD-40), and make sure they operate without resistance. Sharpen each blade with a small diamond file (available at garden centers), trying as much as possible to match the original bevel of the blade. Every 100 cuts or so, swipe the file over the blade a few times to keep it sharp. If you notice that the pruners are crushing the stems and/or leaving a tail, it’s past time to sharpen!
Now, decide what style of pruning you feel comfortable with: (Figure 1) – I find this works well with the way buds are distributed along the cane. Buds are found in the “axel” where a leaf meets the cane; leaves spiral around the cane at about 1.5” intervals. This places outward-facing buds about 4” apart. If I prune lightly to moderately, and if frost damages the tender young growth, then I know I can still re-prune to the next bud down.
In Southern California our rose bushes can grow quite large, so I start with some gross pruning to bring the project down to size. I use loppers to cut every bush down to about 3-feet high. This lets me examine the structure of the bush, and to use my hand pruners to more easily remove canes that are twiggy, dead, crossing other canes, or passing through the center of the plant. I also remove old leaves as I go along so I can easily see the structure of the plant. After removing all that stuff from the interior of the bush you can do the final pruning. Attempt to leave a domed top to the degree possible so the plant will bush out in a pleasing, balanced manner.
There are two kinds of cuts you will make. Some cuts remove the entire branch; these cuts are made flush with the surface of the parent cane. Other cuts simply shorten a cane. It is important to position your pruners so you minimize damage to the plant. Take a look at your pruners and notice that they have a sharp cutting blade (which slices through the cane), and a dull curved non-cutting blade (which holds the cane in place during the cut). These are called bypass pruners, only type recommended. Position your pruners so the non-cutting blade is in contact with the portion of the cane that will be removed, and the cutting blade is on the side of the cut that will remain on the plant. (Figure 2) This will make more sense when you are actually holding the pruners and getting ready to cut! Also, always prune above an outward facing bud with an angled cut. (Figure 3) A word of caution when pruning: Look for the small nests of hummingbirds, as this is the nesting period for two varieties in our area. Also, if you discover praying mantis egg cases on any branches you remove, find a place to put them where they will be undisturbed and hatch out so you can benefit from the offspring!
Be sure to dispose of all cut off material into a green waste bin. Clean the ground thoroughly of all rose debris. Apply a dormant spray to the plants and the soil surface to ward off diseases. Then add 2 to 4 inches of composted mulch to cover the entire garden area.
Frank Brines in a consulting rosarian from Temecula.