All French lilacs originate from Syringa vulgaris, the common eastern-European lilac.
This name derives from varieties bred in France by Victor Lemoine. Look for smooth, three-inch long leaves with a classic Valentine’s Day heart shape. These moderate-growing shrubs are the ones from Grandma’s garden. In June, in full perfume, they are unforgettable.
Flower colours range from white to pinks and deep purples. French lilac flowers last longer and are much more fragrant that many others.
Lilacs are a large and diverse group of plants that flourish in many warmer places in the world. Other notable varieties for Calgary are the Japanese Tree lilac which, a classic, which after decades of growth, can look from a distance like a narrow apple tree, with large, beautiful white flowers and a bark that looks like cherry.
Another favourite is the Dwarf Korean. This lilac stays quite small, around five to six feet for an old one, and has many fragrant pinkish blooms.
There are also many good Preston varieties.
Another group of lilacs is called Villosa. Some of these get very tall and are not known for their flowers as much as the French lilacs. Villosas have larger five-inch long leaves that are indented by their veins.
Plant lilacs where they will be undisturbed and allow them to grow as they wish. This is how you will get the maximum bloom.
If hedged, most of the flower buds will be removed in maintaining the hedge.
Once at a mature flowering age, lilacs bloom every year on last year's buds, exhibiting a classic opposite growing pattern. Most twig tips have three buds, the middle one being the flower and the two side buds designed to be shoots. This is how they grow, always bifurcating, forking into two branches growing from last year's buds, with the flower in the middle.
There is an urban myth about pruning off the spent dead or dying flower stocks growing in the middle of the year’s current shoots. The story goes that if they are removed, the lilacs will flower better and be healthier. This is not true. Although a little unsightly, the lilac has the situation firmly in hand. Later, once completely dry, the dead flower stalks will be abscised—naturally pruned by the plant. Both of the shoots on either side of the flower will continue the pattern with their own three buds.
Old French lilacs are something to see, with their slightly twisted, narrow-stripped bark. In flower, they can’t be ignored, and are one of the very best choices for our harsh climate. There are many denizens of inner-city neighbourhoods, decades old.