How do you care for a lilac bush?
- Grow lilacs in fertile, humus-rich, well-drained, neutral to alkaline soil (at a pH near 7.0).
- Select a site where your lilac will get full sun—at least 6 hours.
- Make sure the site drains well.
- Plant in either spring or fall, although the latter is preferred.
All shrubs fall into one of two categories; some, like many of the hydrangeas, bloom exclusively on new wood and can be pruned to the ground each fall if required. Thus, if you prune at any time other than immediately after flowering, you will cut off next year's blooms.
- Trimming lilacs is best accomplished using clippers. Remove spent blooms all the way to the stems to prevent seeding and encourage more blooms later on. Cut back about a third of the branches. Cut away shoots growing near the ground that may be sprouting from the main trunk.
- Space medium-sized lilacs that are 6 to 8 feet tall at maturity 2 to 4 feet apart. Place larger lilacs, more than 8 feet tall at maturity, about 4 to 6 feet apart. If planting an evergreen California lilac hedge and flowering is not important, space lilacs closer together.
- Shrubs and trees: light pruning. Back to all plant problems. A number of trees and shrubs naturally form a well-branched framework. They require little or no pruning and in fact may be spoilt by harder pruning. Such plants fall into RHS Pruning group 1.
When to Prune Lilacs. New lilac bushes don't require maintenance pruning until they are about 6 feet tall. The time to prune mature lilac plants is just after the flowers have faded. They set the next season's flower buds almost immediately, so late pruning will mean sacrificing next year's flowers.
- Old-fashioned lilacs (Syring vulgaris) may indeed take up to five years to bloom. However, the smaller types, such as Bloomerang or Meyer lilac usually will bloom within a couple of years. Of course, it also depends on how mature the plant is that you start with.
- Potential Damage from Lilac Roots. Damage usually occurs when lilac roots approach the base of the foundation under the soil. Since lilac root systems are shallow, they can only reach the base of shallow foundations. If you have a deep foundation, there is little risk of damage.
- Lilacs are considered deer-resistant, however, meaning that unless the deer in your area are feeling pressure from a lack of available food, chances are they will pass lilacs up in favor of other, more appealing plants. Supposedly, plants like catmint, lavender, thyme, sage and rosemary are also repulsive to deer.
Updated: 4th December 2019