In Which Month Do Lilacs Bloom in North Carolina?

Bloom Month

• Lilac expert John L. Fiala states that on the East Coast of the U.S., lilac bloom time generally begins in late May. Allowing for the fact that North Carolina lies in the south-central part of the East Coast, the earliest-blooming viable lilac varieties planted in the warmer eastern half of North Carolina may open in the first weeks of May or even the last week of April.

Early Bloomers

• The earliest-blooming lilacs are the appropriately named early lilac (Syringa oblata), hardy in USDA zones 3 through 6 and suitable only in the Asheville area in the far west. According to J.C. Raulston, founder of the arboretum at North Carolina State University, the dilatata variety of early lilac (Syringa oblata var. dilatata) also blooms reliably in Raleigh, which is in USDA zone 7a. Early lilac, according to Michael A. Dirr, professor emeritus at the University of Georgia, can bloom as early as April, seven to 10 days ahead of common lilac.

Midseason Lilacs

• Common lilac (Syringa vulgaris), hardy in USDA zones 3 through 7, has long been the most popular species. Common lilac's range does not extend to lowland, coastal North Carolina, but within the hardiness zone, the shrubs might bloom in mid- to late May. Another mid-season bloomer is Persian lilac (Syringa x persica), hardy in USDA zones 3 to 7. According to Dirr, Persian lilacs bloom in mid-May generally, but in Athens, Georgia (USDA zone 7b to 8a), they sometimes bloom from early to late April. This might also be possible in the same zones in central North Carolina.

Late-Season Lilacs

• The late lilac (Syringa villosa), hardy in USDA zones 3 through 7, is also unlikely to thrive in the eastern coastal areas of North Carolina outside its hardiness range. Dirr puts the bloom time at mid- to late May in general. In North Carolina, blooms might open a bit earlier. One of the last species to bloom is Pekin lilac (Syringa pekinensis), hardy in USDA zones 4 to 7. It would bear its creamy white flowers at the end of May in the North Carolina zones where it is hardy.