Because garden growth is at its slowest this month, it's the big month for pruning deciduous fruit and nut trees, cane berries, and grapes. Here’re some basic guidelines and techniques.
Several reasons to prune include removing crowded or crossed branches, opening the center of the tree for better light exposure and airflow, repairing structural weakness, removing vigorous vertical-growing branches (waterspouts or watersprouts), and reducing the height or width of the tree so fruit is easier to harvest without a ladder. Take care to not leave stubs or to overprune in any single year, as this encourages excessive new foliage and less fruit in the upcoming year.
An excellent, inexpensive, and easily-used disinfectant for pruning tools is rubbing (isopropyl) alcohol. Wipe shears with the alcohol after pruning every several cuts to avoid spreading any diseases. Clean the blades extra well before moving to another tree or bush.
Pruning cuts that are under one-and-a-half inches across don't need protective covering. Paint larger cuts with an off-white or sand-colored interior latex paint that has a matte finish, not a glossy one. Black asphalt substances or dark-colored paint, especially on south-facing surfaces, will concentrate the sun's heat--baking and killing the tissue that the tree is trying to heal.
Fig trees are a great place to start since they'll produce lots of figs even if you massacre the tree. It's a great way to reteach yourself how to determine which branches to trim before you move on to the less forgiving peaches, plums, apricots, apples, etc.
Cane berries are most easily pruned when all their leaves have fallen off and the buds have just begun to plump up and show their light pink color. The dead canes and the plant structure are then quite apparent, and the thorns are more easily avoided. When clipping away all the dead growth, be careful to not injure the new pink shoots at the crown.
Prune side shoots just after the third strong bud. This will encourage more sideshoots on those one-year-old canes that will bear flowers and fruit.
Spread and re-anchor the upright canes evenly along the trellis in order to keep the area open for good airflow and promote the even spread of developing foliage that’ll bear blossoms and fruit. At the top of the trellis, prune each strong new cane a foot or so above its point of attachment. This will redirect growth to fruiting sideshoots instead of even longer main vines.
If cane tips have rooted elsewhere in the bed, cut about halfway or so each can be anchored at one of the trellis crosswires. If the tip has rooted outside of the bed, transplant it into the bed in an empty space about a foot away from an existing plant.
Although cutting down all dead and growing vines at the soil level in a clean sweep is an easy approach, it encourages weak bushy growth with only a few berries setting very low on the plant.
Prune grape vines after all the leaves have dropped. The choice of pruning approach depends on the specific varieties and trellis structures you have. Generally, grapes will bear on second-year growth, so prune to encourage this.
Pencil-sized grape cuttings with two sets of nodes can be used to start new vines. When ready to plant the cuttings, trim both ends only one-half inch above or below the node – leaving more may encourage dieback. To identify which end is which, cut the bottom (root end) of the cane flat and the top (foliage end) at a slant. Bury the lower set of nodes in the soil. Don't be concerned if new foliage doesn't appear from the upper nodes until very warm weather, as the strong root system develops first.