Pruning Lilacs

Proper pruning is vital to the flower production, as well as the overall health of your flowering shrubs. Flowering shrubs will bud on new growth to produce flowers in the following growing season.

NOTE: This is part 6 in a series of 8 articles. For a complete background on how to grow lilacs, we recommend starting from the beginning.

Pruning Tips

  • Always be mindful of your pruning cuts; choose to prune just above a bud that is pointing in the direction you would like your growth to continue. This will allow your flowering shrub to internally grow in the shape you want, whether it is a more compact, upright shrub or an open, spreading shrub.

Spring-flowering shrubs:

  • These produce flowers on last year’s growth (what had budded the summer prior) and require early spring pruning before the shrub begins to grow. This is generally recommended while the shrubs are still dormant and before they begin to spring to life again. After the shrubs have flowered and the flowers begin to fade, you will want to then cleanly prune these flowers from the shrub (this is called “deadheading”) which allows for energy conservation and also allows for an aesthetically pleasing appearance of your flowering shrub.

Summer-flowering shrubs:

  • These tend to produce their flowers on what grew that season (typically in the spring) and also require pruning in early spring before they start growing. In this case, you will be pruning out old wood to open your flowering shrub up to receive more light and to cut back on the chance at harboring disease. Flowers have a tendency to form and thrive where they receive the most light, so the more light that is accessible to your flowering shrub the more flowers it may produce overall.
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