Lilac season arrived a bit ahead of schedule in North America. In your Road Trips Gardener‘s back yard, the peak blooms are fading to green.

The Hulda Klager Lilac Festival takes place April 21 through May 13, 2012, at Hulda Klager Gardens, 115 South Pekin Road, Woodland, Washington (map).

The International Lilac Society’s annual meeting and convention will be in Nancy, France, May 3 through 5, 2012. This is the first time the ILS convention has been held outside North America.

Nancy is the home of Victor Lemoine. He and his descendants are credited with developing 200 new lilac cultivars, including double French hybrids, and first Hyacinthiflora lilacs. The ILS has a slideshow of Lemoine lilacs online.

Lombard, Illinois, has an entire city park devoted to lilacs, and an annual festival is held there. This year’s Lilac Time is scheduled for May 5 through 20, 2012, in Lilacia Park, 227 West Parkside Avenue, Lombard, Illinois (map).

Another Lilac Festival takes place May 11 through 20, 2012, in Highland Park, 171 Reservoir Avenue, Rochester, New York (map).

Lilac Sunday is May 13, 2012, at the Arnold Arboretum of Harvard Arboretum, Boston, Massachusetts (map).

Those of you who are lilac fans definitely should plan a drive to the Royal Botanical Gardens, 680 Plains Road West, Burlington, Ontario, Canada (map), to see the Katie Osborne Lilac (Syringa) Collection (Lilac Dell and Lilac Walk) on one of the last two weekends in May.

The Gardens are home to the largest lilac collection in the world. RBG is also the home of the International Registration Authority for new lilac cultivars, and a site for their display and evaluation. From the 26 wild lilac species native to eastern Asia and southern Europe, breeders have developed over 1,600 cultivated varieties.

Also in Canada (but out West), look for the Fourth Street Lilac Festival in Calgary, Alberta, on May 27, 2012.

The Lilac Festival on Michigan’s Mackinac Island is set for June 8 through 17, 2012.

(Photo courtesy of International Lilac Society)