To prune roses, cut out all dead wood, spindly canes, and canes that grow toward the center of the bush or outward parallel to the ground and branch upward. Remove the weaker branch if two cross. Remove all shoots that grow from below the graft union (suckers). Always cut to a bud or remove the entire cane. Once all the undesirable growth has been pruned, thin the remaining canes as necessary. Cut canes above a bud facing the outside of the bush.
Grape vines should be pruned within the next several weeks in this area. The most important factor influencing the pruning method used is grape variety.
Varieties, such as Thompson and Flame seedless, are cane-pruned. Cane-pruned vines should be trained to have a single trunk that produces several lateral shoots (arms) 2 to 3 feet above ground level; the 1-year-old canes will grow from the arms.
To cane prune mature grapevines, remove the wood that produced fruit last year. If possible prune last year's fruitwood near its origin on the arms. Occasionally you will need to leave a new cane on last year's fruitwood to have the desired number of fruiting canes for the coming season. The canes that will be next year's fruitwood should be left 12 to 15 buds long. The number of canes will depend upon the vigor of the vine.
Commonly, four canes are left on weak vines and seven canes are left on vigorous vines. About two shoots per arm to be removed should be cut so there are only two buds on the shoot (spur). These spurs will produce shoots this year that will be next year's fruitwood. When selecting canes and spurs, consider the overall health of a cane, the distance of the cane or spur from the trunk and impact of a cut on the shape of the vine.
In general, wine grape varieties Zante Current and Muscat of Alexandria are spur-pruned. On spur-pruned vines, 1-year-old shoots are cut back so there are two buds on each young shoot (spur). Spur-pruned vines may be cordon-trained, in which two or four older shoots (cordons) are wrapped around a wire or two. Above the cordons will be another wire for this season's growth to climb. Low-vigor varieties may be head-trained, in which each spur is on short older shoots produced directly from the trunk and no wire is used. Five to nine spurs for head-trained vines and four to six spurs per cordon for cordon-trained vines are typical.
Fig trees should be topped about 24 to 36 inches above ground level when young to encourage lateral shoot growth, which will become the structural branches. The trees should be pruned annually for the first five years to encourage upward and outward growth. Mature trees should be pruned at this time of year by thinning branches and by cutting the tips of long shoots to maintain the shape of the tree. However, the first crop of figs is produced at the ends of last year's shoots, so leave some full-length branches.
Olive trees should be trained while they are young by selecting one shoot as a trunk and cutting out all other shoots growing from the ground level. If not pruned, a young olive tree will put out several shoots from the ground level that may break under the weight of a heavy crop or during high winds. Leave three lateral shoots, which will become the structural branches. If olive production is the goal, these branches should be left 12 to 24 inches above ground level. If it is to be a shade tree, you may want to train the tree so the structural branches are further from the ground. On mature trees, the dead branches should be removed. Young branches could be removed to reduce the density of the canopy. It is better to prune a little each year than to prune severely less frequently.
In addition to the plants mentioned in this article, peach and nectarine trees should be pruned every year. Others, such as citrus, should be pruned only to remove dead wood and suckers. Mulberry, ash and many other ornamental trees should be pruned when young to establish the desired structure of the tree, but once mature, little pruning is required. Severe pruning of these trees will create wounds that could serve as an entry site for certain insects and disease-causing fungi that could kill the tree, and if pruned while the temperatures are high, branches will sunburn.
The Cooperative Extension serves all residents of the Imperial Valley.