I grew up not far from Rochester, NY, which holds a big lilac festival every year.  It was a perfect celebration of spring in a part of the world that gets a lot of winter.

In my Zone 6 garden, the lilacs start blooming along with the mid season tulips and help to provide color after many of the showy spring flowers--like daffodils--have folded up their petals and begun the first steps on the road to dormancy.  Taken on their own, the bushes are pleasant enough, but not much to write home about.  The leaves are an endearing heart shape, but the branches can grow gangly if not tended every year.   Lilacs are not as unattractive out of flower as forsythia, but they don't provide more than one season of real interest.

But lilacs more than make up for their relatively short season of interest by covering themselves with the most elegant, beautiful, fragrant array of tiny flowers imaginable.  Arranged into large panicles or flowerheads, they are enough to make you want to cut armloads to bring into the house.  Unlike some highly scented flowers, lilacs don't seem to become overpowering even when you put a large vase of them n a relatively small room. 

I am especially fond of the old favorite 'President Lincoln', which is a cultivar of the "common" Syringa vulgaris.  The President, like its namesake, grows tall.  The flowers are blue-purple and exceptionally fragrant.  Also, like its namesake, 'President Lincoln' can stand up to hard times, especially in the form of cold winter temperatures.  Pruning a third of the mature branches back every year is all it takes to keep it in shape.  This kind of pruning also allows for good air circulation, which keeps powdery mildew, at bay. 

Out in the country, almost every old farmstead has a lilac growing somewhere near the door.  It is a custom that deserves a renaissance.