I hear many complaints about how the tree pruning crews who perform line clearance brutalize trees. Not only can poorly maintained trees in high voltage lines cause outages, but they can be extremely dangerous. Before I continue I should say that only trained professionals should prune trees near the PG&E high voltage lines.

Unfortunately, like many intensive horticultural practices, real topiary is almost never seen anymore. Traditional topiary, as it was perfected by the English, involved intricate shearing of dense shrubbery into less than traditional and often whimsical shapes.

In winter, I try to explain why it is important to prune dormant trees, particularly fruit trees, prior to the end of their dormancy. Fruit trees, which were not pruned properly last winter may now be experiencing problems as the weight of the developing fruit is more than the limbs can support.

Culling, removal of superfluous fruit, is similar to deadheading, but diverts resources to remaining fruit rather than to floral or vegetative parts. Many fruit trees benefit from selective culling while fruit is beginning to develop during more productive seasons.

Deadheading, the removal of fading flowers, is important for many species to conserve resources that would otherwise be utilized by developing fruit structures. For example, maturing rose hips (the fruiting structures of roses) require so many nutrients that there is not enough left for continued bloom, which is therefore inhibited if rose hips are not removed.

Pruning of fig trees should be done during cold weather if possible. Slow circulation allows wounds to “cauterize” rather than continue to bleed as they often do during warm weather. The autumn figs eventually appear on new growth of the immediately preceding summer.

Unlike softwood and semihardwood cuttings that exploit the active growth that occurs between spring and summer, hardwood cuttings are ‘stuck’ (installed in their rooting medium) when inactive so that they can emerge slowly from dormancy in their new environment, producing new adventitious roots as needed.

Winter is the best season to prune because the trees are dormant. As dormancy ends, growth is concentrated among remaining stems and can be left to complete a year (growing season) of a natural growth and fruit production cycle.

Winter pruning is also preferred by trees that bleed if pruned while active, such as fruitless mulberry and fig or trees that produce tender new growth prior to frost if pruned at the wrong time, such as jacaranda.