Lilacs are great large shrubs for northern landscapes. They require little care, are long lived, and provide welcome color and fragrance in spring. You may not realize that by planting different selections of these old-fashioned shrubs you can have blooms for six weeks or more, and that they come in many colors other than lilac. In my USDA zone 4 garden, I have lilacs that begin bloom on average the second week of May, and the last ends bloom the last week of June. There are two general groups of lilacs, the early bloomers which bloom in mid to late May in this zone (sooner in warmer zones), and the late bloomers in early to mid June in this zone. The early bloomers are mainly cultivars (cultivated varieties) of the common lilac species (Syringa vulgaris), while the late bloomers are often cultivars of various species or the Preston hybrids ( Syr/inga x prestoniae/). The Preston lilacs were first hybridized by Isabella Preston at the Experimental Farm in Ottawa, Ontario. They are crosses between two species, and include such popular cultivars as the purple Donald Wyman, the white Agnes Smith, or the pink James MacFarlane. Lilac specialists have come up with seven color groupings for lilacs that sometimes are seen with Roman numerals. Unless noted, these examples of good lilac choices are of the common lilac. The first group are the white lilacs such as the single common lilac Alba, or the single Preston hybrid Agnes Smith, Edith Cavell is a white double, as is Mme. Lemoine. Primrose falls into this group, although the buds and flowers are a unique light yellow. One of my favorite lilacs is the Russian hybrid Krasavitsa Moscovy, seen also by its English name Beauty of Moscow. The pink-lilac buds open to double white blooms tinged with lavender. Look for these and other cultivars and colors the next time you visit a nursery, complete garden center, or public lilac display garden such as at the University of Vermont Horticulture Research Center (pss.uvm.edu/dept/hort_farm/). If you have just the common lilac in your landscape, why not add some other colors? If you dont have any, why not start adding them if you have the room, sun, and well-drained soil.