Common lilac is a USA-NPN calibration plant species. Calibration species have broad distributions and are ecologically or economically important. The USA-NPN integrates observations on calibration species to get "the big picture" of plant responses to climate across the nation. Observers can obtain these lilacs from nurseries, or may already have them growing on their grounds. These lilacs are not cloned and are not distributed through the USA-NPN Cloned Plants Project. However, their response to climate is generally uniform and similar to cloned lilacs and for that reason are considered part of the Cloned Plants Project.
In addition, common lilac has been selected for monitoring by our partner, Monarch Watch, because it is an important nectar plant for monarch butterflies. If you are a member of Monarch Watch, please see the monitoring instructions on the Monitoring Partners page.
Common lilac is an introduced, perennial, deciduous shrub that grows between 12 to 16 feet tall. The flowers are mostly white, lilac, or purple, and pleasantly fragrant in long terminal panicles.
Common lilacs (also called "hedge" or "old-fashioned") are often sold in nurseries or are found already growing on homesites. They have leaves that are somewhat heart-shaped and are much wider than the leaves of cloned lilacs.
You should observe...
Here are the phenophases you should observe about this plant.
In at least 3 locations on the plant, an emerging leaf is visible. A leaf is considered "emerging" once the widest part of the newly emerging leaf has grown beyond the ends of its opening winter bud scales, but before it has fully emerged to expose the petiole (leaf stalk) or leaf base. The leaf is distinguished by its prominent midrib and veins.
|All leaves emerged
For the whole plant, the widest part of a new leaf has emerged from virtually all (95-100%) of the actively growing leaf buds.
For the whole plant, at least half (50%) of the flower clusters have at least one open fresh flower. The lilac flower cluster is a grouping of many, small individual flowers.
For the whole plant, virtually all (95-100%) of the flower clusters no longer have any unopened flowers, but many of the flowers are still fresh and have not withered.
|End of flowering
For the whole plant, virtually all (95-100%) of the flowers have withered or dried up and the floral display has ended.
When to Start Observations: In the middle of winter, lilac buds are desiccated (dried out) and appear somewhat shriveled (mid-winter bud). In late winter, after conditions begin to warm, the buds hydrate (swell due to becoming moist), and the tips open slightly (late winter bud). The best way to know when to start looking for the first emerging leaves is to watch for these two events. Once the buds have swelled and the bud ends are slightly open and a bit green, the next round of warm weather can force the first leaves to emerge.
Monarch Watch participants should observe the "open flowers" phenophase.
Although Syringa vulgaris is native to southeastern Europe, it has been naturalized in many other regions of the globe.The plant has been used ethnobotanically to reduce fever and treat malaria, as a perfume and a tonic, and in homeopathy.
Gardens with this plant