Winter Pruning Techniques for Chestnut Trees in Full Bearing Period

    Doing a good job of winter pruning of chestnut trees in the full bearing period is an effective measure to prolong the full bearing period and prevent the occurrence of alternate bearing. 

    I. Choosing the Pruning Time

    The period for winter pruning of chestnut is best from half a month after leaf fall to half a month before bud break the following spring, that is, from mid-December to early February of the next year, but pruning should be postponed when freezing weather occurs. 

    II. Removing Inferior Branches

    When pruning, first cut out all inferior branches such as diseased and pest-infested branches, overlapping branches, dead and dry branches, crossing branches and thin weak branches, so as to improve ventilation and light conditions within the canopy and concentrate nutrients to make the shoots thick and well filled. For the terminal branches and the long branches of their scaffold branches, about 50 cm should be retained each year for heading back, in order to promote new shoots, increase the number of bearing mother branches, and at the same time control the speed at which the bearing position moves outward.
 
    III. Thinning Dense Bearing Branches

    For bearing mother branches that were previously too dense, part should be thinned out, or part should be headed back as renewal branches. Before the canopies touch, about 15 bearing mother branches may be retained per sq m of canopy area; after the canopies touch, about 12 bearing mother branches should be retained. For bearing mother branches that grow too vigorously, appropriate heading back should be done to promote new shoots from their lower parts; for bearing mother branches that have aged, retraction should be carried out so as to concentrate nutrients to promote new shoots and cultivate them into bearing mother branches to continue bearing fruit. 

    IV. Adapting to Local Conditions

    When pruning chestnut, it should be done according to the soil quality and tree vigor. Where the soil is fertile, the soil layer is deep and the tree vigor is strong, light pruning is preferable to heavy pruning, and the opposite applies otherwise. If winter pruning can be carried out together with fertilization at the same time, twice the result can be achieved with half the effort.