The question of whether lilacs are trees or bushes often sparks debate among gardening enthusiasts. The truth is, lilacs are typically shrubs, but under certain conditions, they can exhibit tree-like characteristics. This depends heavily on the variety, pruning practices, and environmental factors. Let's delve deeper into the nuances of lilac growth.
The Predominant Form: The Lilac Shrub
Most lilac varieties are naturally multi-stemmed shrubs. They grow multiple stems from the base, creating a rounded or spreading form. This is the most common growth habit observed in home gardens and landscapes. These shrubs typically reach heights ranging from 6 to 15 feet, depending on the cultivar. Their wide, bushy shape contributes to their popularity as foundation plantings and hedging. Think of the classic image of a lilac bush – that's the norm.
Factors Influencing Shrub-like Growth:
- Genetics: Different lilac cultivars have varying growth potentials. Some naturally stay more compact, while others are inherently bushier.
- Planting Density: Planting multiple lilacs close together encourages competition for resources, resulting in a denser, shrub-like form.
- Pruning Practices: Regular pruning, especially the removal of lower stems, can maintain a more compact, shrub-like structure. Conversely, neglecting pruning can lead to a more sprawling, less defined shape.
The Exception: Lilac Trees
While less common, it's entirely possible to train a lilac into a small tree form. This usually requires careful pruning and selection of a vigorous cultivar. Here's how:
Creating a Lilac "Tree":
- Choosing the Right Cultivar: Opt for a variety known for strong central leader growth. Some cultivars are naturally more inclined to develop a dominant central stem.
- Selective Pruning: From a young age, consistently prune away competing stems, encouraging a single, strong central leader to develop. This involves removing all side shoots and branches up to a chosen height.
- Staking: Support the central leader with a stake to prevent it from bending or breaking under the weight of its foliage.
- Ongoing Maintenance: Regularly prune to maintain the desired shape and remove any suckers or branches that emerge from the base.
Even with diligent pruning, a lilac "tree" will likely remain relatively small, rarely exceeding 15-20 feet. The appearance will be more of a multi-trunked small tree, as completely eliminating all side branches is challenging and unnatural for the plant.
Conclusion: Lilac Versatility in the Garden
Ultimately, whether you consider a lilac a tree or a bush depends on how it’s grown and managed. While most remain delightful and classic shrubs, with careful planning and pruning, you can indeed cultivate a lilac with a more tree-like structure. The choice is yours, offering flexibility in design for your garden landscape. This versatility makes the lilac a truly adaptable plant, suitable for a wide range of gardening styles.
