The common lilac is NOT a good plant for your honey bees. While not a native plant, it is readily visited by native bees, especially the bumble bees. Plant it for the native bees, the butterflies, hummingbirds and the bumblebees. Plant it too because it smells good and is pretty!
There are better lilacs attractive to honey bees, such as Miss Kim , Palibin, and the Japanese tree Lilac.
Name: Common lilac
Type: Deciduous shrub
Zone: 3 to 7
Spread: 6-12 feet
Bloom Time: May
Bloom Description: Purple, single, white-edged petals
Sun: Full sun
Suggested Use: Hedge Flower: Showy, Fragrant, Good Cut
Attracts: Hummingbirds, Butterflies
Tolerate: Deer, Clay Soil
Easily grown in average, medium moisture, well-drained soil in full sun. Tolerates light shade, but best bloom is in full sun. Intolerant of full shade. Prefers moist, fertile, organically rich, slightly acidic to slightly alkaline soils with good drainage. Avoid soggy soils. Needs good air circulation. Prune as needed immediately after flowering. To the extent practicable, promptly remove faded flower panicles before seed set. Best grown in cool summer climates. Not recommended for planting in the hot and humid conditions of the deep South in USDA Zones 8-9. Promptly remove root suckers, particularly on grafted plants, to maintain plant appearance and prevent unwanted colonial spread. Propagate by cuttings in spring.
Syringa vulgaris, commonly known as common lilac, is an upright, multi-stemmed, suckering, deciduous shrub in the olive family that typically matures to 12-16’ (20’) tall with a spread to 8-12’ (15’) wide. It is native to open woodlands, rocky hills and scrubby areas in southeastern Europe, but has been widely cultivated throughout Europe (beginning in the late 1500s) and North America (brought over by colonists in the early 1600s). It is particularly noted for its mid to late spring (May) bloom of very fragrant flowers.