There is a wide variety of cultivars within the species Taxus cuspidata, sometimes known as the evergreen Japanese yew. Capitata, for example, may grow to a height of forty feet, which makes it challenging to prune a mature plant. On the other side, Densa stops growing when it reaches a height of 4 feet, and Nana stops growing when it reaches 15 feet. Yews, in contrast to other evergreens, are able to recover effectively after severe pruning, even if their recovery is somewhat gradual. The optimal moment for you to prune yours is contingent upon the target that you have set for yourself.
There are a number of fungal diseases that may affect Japanese yews, including sooty mould. In addition, the plants may be infested by black vine weevils. Aside from that, as the yew matures, its stems die, and breaking may be caused by wind, snow, and ice. Regardless of the season, if there is a risk of disease, death, or injury, you should prune the affected areas as soon as you notice the problem.
The first flush of new leaves appears on Japanese yews in the spring, and then another one appears around halfway through the summer. Trimming your plants in the early summer, when the foliage has become a dark green colour, is the best time to exercise shape control over your vegetation. At the middle of August, repeat. Cut the stems at an angle of 45 degrees, one quarter of an inch above a blossom. This kind of pruning is not required to keep yews in good health; rather, it is done for aesthetic purposes.
If you do not want the “Capitata” kind of Japanese yew to get too tall, trim the top of the plant whenever new growth appears. By holding your shears at an angle, you may carefully prune this plant while preserving its characteristic pyramidal form. According to the University of Wisconsin Cooperative Extension, when pruning young evergreen wood, you should cut it down to two-thirds of its original length.
Plant diseases may sometimes live on their own without a host plant. However, as soon as they have the opportunity, they will move to your living yew and impede its growth. Therefore, before you start cutting into the wood, it is a good idea to sanitise the blades of your shears. One part bleach should be added to nine parts water in a bucket. Before you begin trimming, submerge the blades in the liquid mixture, and do it again after each cut. Use a cloth that has been dampened with alcohol to clean the tool as an alternative.