The Best Time and Methods for Pruning Plum Trees

To achieve high yields from plum trees, in addition to basic water and fertilizer management, the tree body must also be pruned to promote nutrient absorption by all branches, ensure fruit production the following year, and increase benefits. So when is the best time to prune plum trees? How should you prune?

Plum Tree Pruning Time

Plum trees can be pruned in summer and winter, but the pruning method differs for each season.

Summer Pruning

Summer pruning can generally be carried out 3 to 5 times: the 1st time is after spring bud break, mainly to remove buds in improper positions and the weaker of twin buds, reducing ineffective branches and saving nutrients; the 2nd time is after petal fall. Combined with flower thinning and fruit setting, remove overly dense branches and control competing branches; the 3rd time is after pit hardening, when vigorous growing branches are cut back to encourage secondary shoots and increase the fruiting area; the 4th time is in early to late autumn, when excess secondary shoots are cut back or thinned out, and long fruiting branches are pinched to moderate vegetative growth and promote flower bud differentiation. When summer pruning is done carefully, it can greatly reduce the workload of winter pruning and has a clear effect on saving tree nutrients, maintaining balanced tree vigor, increasing branching order, and promoting flower formation and fruiting.

Winter Pruning

On the basis of summer pruning, supplementary pruning is carried out, mainly to maintain the tree shape and balanced growth, preserve the subordinate relationships among branches at all levels, and regulate the balance between vegetative growth and reproductive growth.

Plum Tree Pruning Methods:

1. Pruning methods during the young tree stage

Newly planted plum trees are in the young tree stage and grow very vigorously, and the main trunk branches form very easily. Therefore, during pruning, care should be taken to let them form a good tree shape and expand the crown of the young tree. To ensure early fruit production, pruning should not be too heavy; it is enough to achieve normal nutrient transport and moderate the growth of tender buds. For new seedlings, the cutting-back method can be used, that is, cutting off part of a one-year-old branch, about one quarter, which can moderate branch growth, stimulate more medium and short branches, and cultivate multiple types of branch groups. After one-year-old branches are cut back, their growth capacity, growth direction, and extension direction differ greatly. For upright branches with plump cut ends, vigorous shoots tend to sprout after cutting back, and these vigorous shoots can be used to develop the tree's framework; other weak shoots derived from them can be cultivated as fruiting groups. Although cutting back is not conducive to the formation of flower buds in fruit trees, a moderate amount of cutting back on weak branches can increase the total number of buds and branches in the fruit tree and raise its yield.

2. Pruning methods during the early fruiting stage

Plum trees two to three years after planting have already entered the fruiting stage and begun to produce a crop. The purpose of pruning at this stage is to improve the tree's form, expand the crown's range, and cultivate as many fruiting branches as possible. Because winter in the Fujian area is relatively warmer than in most northern regions, but temperatures are still fairly low, branches should be cut back as much as possible during pruning to reduce branch density, which can improve ventilation conditions for the plum tree, increase light, and save nutrients. However, the amount cut back should not be too much, to avoid causing excessive vegetative growth. For branches inside the crown, observe their growth direction and position, and as long as the direction is suitable, try not to prune them.

3. Pruning methods during the full fruiting stage

After plum trees enter the full fruiting stage, the main branches have already grown large and the tree's growth is relatively moderate. At this time, improving the nutrient composition of the plum tree is a principle that pruning must follow. After pruning, the tree's morphological structure has already formed, and this is the period of the greatest plum yield. In the full fruiting stage, plum yields increase year after year and reproductive nutrient consumption is excessive. At this stage, as many main and lateral branches as possible should be cut off to ensure sufficient light and ventilation. During this period, on the basis of strengthening water and fertilizer management, pruning should be used to control the outward movement of fruiting sites, renew and cultivate fruiting branch groups through delayed pruning, thin out overly dense upright branches, improve internal light conditions, maintain robust tree vigor, and extend the years of the full fruiting stage. Delayed pruning means leaving some one-year-old branches without any pruning and letting them grow naturally, slowing the tree's growth, which can promote flower bud differentiation. For delayed pruning of upright branches, they must first be flattened or twisted and injured from the base, otherwise the effect is poor. Branches subjected to delayed pruning must be promptly cleaned up after flowering and fruiting, either by cutting back or by renewal pruning, to keep the tree shape complete and attractive and favorable for fruiting.

4. Pruning methods during the aging and renewal stage

After the full fruiting stage ends, as the plum tree's growth time continues to increase, the growth of new buds and branches gradually decreases, the tree body begins to show signs of aging, branches begin to die, plum quality and yield gradually decline, and fruit size also begins to shrink. In order to renew the main branches in time, it is very necessary to strengthen nutrition for the fruit tree. Very thick old branches can be sawed off directly from the base. After a period of time, new branches can quickly sprout from the cut, and branches with excellent angles and extension directions can be selected and specially cultivated into new trunks and fruiting branch groups, restoring fruiting capacity and extending the fruiting years.