Flowering Times of Lilacs
Lilacs flower at different times of the season. By using different specie lilacs and dwarf lilacs it is possible to extend your flowering time over a 6-8 week period and some lilacs do repeat bloom making it a more diversified lilac season. Many new dwarf lilacs have come out over the past few years that do repeat bloom. Please note that no lilac can continuously bloom. The lilacs that do rebloom need to have all new growth pruned back by 2/3 after flowers have faded and then will will begin a new growth cycle usually within 2 weeks. The lilacs that do rebloom have the capability to produce flowers on new growth and not only on old growth as all the other lilacs. Thus within a 7-9 week period depending on heat you can have more flowers. The second bloom time is almost as profuse as the first and successive blooms will be more sparse over the summer and fall.
Lilacs will usually flower for a period of 2 weeks from flower bud color and until they fade. A cooler spring will make them last longer. Cooler sunnier springs means a better fragrance of the plants and warm rainy springs usually does the adverse affect. Soil types will also affect fragrance and color. Lilacs are like wines. It all depends on climatic areas for colors and fragrances.
Even if more sparse its wonderful to see some bloom in late August and even in Late October.
Because lilacs will bloom at different times in the spring depending where you are there is no way to specifically say mid May for early lilacs as an example. In our section of Parks and Collections there will be a reference to when that specific collection is in flower. There will also be a reference to different cities or countries when available. If you have a collection or would even just like to be on our map for flower times just contact at the email below and let us know when your specific lilacs usually flower.
Early Bloom
Sub specie
oblata and all its forms oblata and dilatata
vulgaris 'Rhodopea'
Mid Season Bloom
Within 7-10 days after early bloom
pubescens meyeri, patula, julianae, potanini, microphylla and all cultivars that fall under these headings
Late Blooms
2 weeks after mid season
villosa villosa, emodi, wolfii, josikaea, komarowii, nanceiana, tomentella, yunnanensis, henryi, josiflexa, prestoniae, swegiflexa,  and all cultivars that fall under these headings
Very Late Blooms
2 weeks after late blooms

email address: selectpluslilacs@yahoo.ca

Discovery Time Table of Specie Lilacs
afghanica J. Aitchison 1871 Afghanistan
emodi R. Blinkworth 1831 Nepal, Pakistan, China
josikea Rosalia, Baronne von Josika 1826 East of center of Europe
komarowii G. Potanin 1893 China: Gansu, Sichaun, Yunnan
mairei E. Maire 1914 China: Sichuan, Yunnan
oblata A. Bunge 1831 Korea, China
pinetorum G. Forrest 1831 China: Sichuan, Yunnan
pinnatifolia E. H Wilson 1904 China
prolacinata F. Meijer 1989 China: Gansu, Qinghai
pubescens P. Kirilov 1831 Korea, Japan, China
reticulata C. Blume 1850 Korea, Japan, China, Russia
sweginzowii Potanin-Berezovski 1894 China: Sichuan
tibetica G. Potanin 1885 Tibet
tomentella Bonvolot and Prince Henri D'Orleans 1910 China
villosa Pierre D'Incarville 1750 China
vulgaris Rochel 1828 Bulgaria, Rumania, Serbia
wardii F. Ward 1913 China, Tibet
wolfii G. Potanin 1910 Korea, China
yunnanensis J. Delavay 1887 China