The California Lilac is a dependable ornamental shrub that never fails to produce clusters of calming blue flowers year after year. Like other plants, California lilacs can benefit from pruning to become fuller and assume an aesthetically-pleasing shape.
Here is a short guide on when and how to prune California Lilac.
When Should You Prune a Californian Lilac?
As a general rule, you should prune a Californian lilac after it’s finished flowering.
The California Lilac is also known as Californian lilac or ceanothus, and it’s divided into evergreen and deciduous varieties, as well as early and late flowering cultivars. For early flowering species, it’s recommended that you do a light pruning immediately after the blooms are spent.
The ones that flower later on, such as during early winter or fall, will have to wait until the first sign of spring to get pruned.
Evergreen ceanothus can be cut back after its flowering period is over. The deciduous variety of California lilac can be pruned in early spring or when the risk of frost has passed. You can also wait until mid-spring or when the temperatures have warmed up to give your shrub a cut.
It’s worth noting that deciduous ceanothus benefits more from regular pruning than the evergreen variety. You should only give evergreen Californian lilacs a trim when it loses their shape or form.
How Do You Prune a California Lilac?
The pruning process and technique will vary depending on whether you have an evergreen Californian lilac or a deciduous species.
Evergreen types won’t survive hard or severe pruning, while a deciduous California lilac will love it when you cut them down to about 50 cm and above the lowest branching area.
How to Prune Evergreen California Lilac
Evergreen California Lilacs do not require regular pruning, and most of the time, it’s done only to produce a pleasing aesthetic effect for your landscape. Use the correct pruning and cutting tools so it will be clean and your shrub won’t get too damaged. Remember to sanitize and clean them afterward so they last a long time.
You can trim the shrub to the shape you want and remove weak shoots and dead leaves in the process. It’s worth noting that you should never cut back beyond green growth and leave the old branches, or you’ll likely end up with a stump. Just pinching the flowering tips and removing branches that don’t have leaves or flowers should be fine.
Late flowering shrubs can be cut back to a third in spring, while early flowering varieties can be pruned as soon as all the flowers are spent. Remember not to cut back too much (stay in the green) and your Californian lilac should be fine and bounce back with more blooms than before.
How to Prune Deciduous California Lilac
The deciduous species of California Lilac can be treated as a traditional deciduous shrub. You can cut it back in early spring and bring it down to size (about two-thirds and not more). Mature specimens can take severe pruning to about a half in size.
For shrubs that have become too big, you can cut it to just 50 centimeters from the ground and above branching junctions. Otherwise, it’s recommended that you do routine pruning by cutting out main stems and external-facing shoots until you have the shape you want.
Along the way, trim out dead branches and leaves so your Californian lilac will look more presentable in the end. The more you prune the deciduous variety of California lilac the bushier it becomes. You’ll get treated with a veritable shower of blue for your hard work.
Related Article: Planting Lilac in Clay Soil