Prince George’s Dominion Experimental Gardens host hardy Preston lilacs

These tough and beautiful lilac plants have proved themselves in northern gardens

Credit: Barbara Rayment

Lilacs provide a feast of colour at the Dominion Experimental Farm Site in Prince George

Lilacs provide a feast of colour at the Dominion Experimental Farm Site in Prince George.

A pioneering plant breeder’s aspiration to create the perfect Canadian lilac continues to delight gardeners to this very day

There are few things as perfect as springtime and being surrounded by masses of old lilacs in full and fragrant bloom.

Ninety years ago, Isabella Preston made the first recorded cross of the extremely hardy Syringa villosa and the lesser-known but beautiful Syringa reflexa (aka S. komarowii ssp. reflexa). Preston’s work at the Central Experimental Farm in Ottawa with lilies and irises and ornamental crabapples, among other species, resulted in a wide variety of new hardy cultivars suitable for the cold-climate country that she had adopted. Her most lasting and best-known legacy remains that strain of hardy late-blooming lilacs now known collectively as “the Prestons” (S. x prestoniae). 

Several decades after Preston began her lilac-breeding work, a shipment of lilacs arrived at the Dominion Experimental Farm site in Prince George. Planted out in heavy clay soil in a cold and unforgiving climate, those lilacs prospered and are still alive today as testament to the hardy spirit of Canadian plant breeders and plants. The records have been lost, so we don’t know exactly when they arrived, or if the specimens we were sent are the original Preston varieties or second-generation seedlings, but there is no doubt as to their beauty and toughness – and longevity. 

A visit to the old Experimental Farm site in lilac season is a heady experience, with over 40 mature specimens in bloom, shades of pink and purple and lavender and lilac, and all with the fragrance that seems to have been bred out of many modern cultivars. They are all huge bushes with the elongated and almost leathery leaves that set them apart from the more common French hybrid lilacs. Some have been lovingly tended by tenants on the site over the years and decades, some have been butchered by well-intentioned but inexpert pruning and others don’t look like they have been pruned at all in the 20 or so years since the last groundskeeper retired. They are all still blooming.

A blossom reminiscent of the Syringa reflexa parent.

Efforts are being made to clone this unique collection for planting at a second site in the Prince George area, although some of the specimens are proving more difficult to root from cuttings than others. They apparently vary in this as well as in flower shape, size and colour. This work, one of the many projects being taken on by the Prince George Master Gardener group, will continue as long as access to the site can be maintained.

In the meantime, a number of Preston lilacs are readily available on the market. Of the 81 varieties registered by Preston nearly a century ago, at least half a dozen are still relatively easy to find, including ‘Coral’ (lavender-pink), ‘Redwine’ (magenta) and ‘Royalty’ (purple). Second-, third- and fourth-generation Preston lilacs from other breeders carry on the tradition, with popular favourites being ‘Donald Wyman’ (rosy-purple), ‘James McFarlane’ (pale lavender-pink) and ‘Minuet’ (a compact and upright branching lilac-purple form). ‘Miss Canada’ is easily the best deep-pink lilac in existence, classified in lilac terminology as magenta, sometimes described as ‘China-rose’, but definitely a rich pink.

These tough and beautiful plants have proved themselves in northern gardens. They sucker less than the French-hybrid lilacs, survive harsher conditions and extend the lilac season by several weeks. Preston, who died in 1965 at the age of 84, would be pleased that her creations still bring so much happiness, I think. They are a fitting tribute to a great Canadian woman and pioneering plant breeder. 

Syringia x prestoniae is hardy to zone 2.

Barbara Rayment gardens in Prince George, where she grows and experiments with a wide variety of hardy plants, when not teaching the Master Gardener course or writing. The 2nd edition of her book, From the Ground Up: A Horticultural Guide for Northern Gardeners, is now available.