A Seasonal Display Primer

By Jim Mack, Head of Horticulture, Royal Botanical Gardens.

The transition through the seasons may be slow and subtle, but from a horticultural point of view, it is always changing. Though we’re buried in snow at the moment, it won’t be long until the first Snowdrops can be seen. By late April spring will awaken in our display beds with an explosion of Crocus, Tulips, Narcissus, Grape Hyacinths, and a plethora of minor spring bulbs.  Mid-May marks the return of our seasonal summer annuals and ornamental grasses, and the calendar will move through its annual cycle on cue. On any given day in late September or early October our display beds are bursting at the seams with bountiful annuals, and the next day with pumpkins, straw bales, and chrysanthemums, reflective of the expected seasonal cues. Keeping with the seasonal progression model, come late October, mums are cleared out, beds are levelled, and spring bulbs are hidden away beneath bare earth, signifying the start to winter’s rest beneath blankets of falling leaves, and later, snow.

Behind the scenes, our horticultural planning is continuously in motion as plans and orders are prepared many months in advance for each of these transitional changeovers. This happens in concert with the collaborative efforts of several other departments in support of the overarching theme for the year ahead. In 2021, RBG will continue planning its horticultural displays to complement the Come to Your Senses theme. Staff were busily scrutinizing seed catalogues filled with the newest varietal choices – including some that RBG has already trialed in its All-America Selections Display Garden as well the Annuals Trial Beds (in partnership with the University of Guelph). We look for just the right plants to deliver the desired look, sound, and scent in each display bed. A master list of the staff choices for each garden is compiled, verified, and ordered from our vendors, usually by Christmas. These orders include seed, rooted cuttings and “plugs” (pre-sown seeds bought in as small plants).

Production of our annuals follows a schedule that is arrived at by working in reverse, that is, counting back from the time the finished plant is needed by our gardens staff. In between the arrival of orders and getting plants in the ground, our plant propagation and production staff take delivery of the propagules and vegetative plants in our production greenhouses. These arrive at their appointed time between January and February, to be grown on to finished size. All is choreographed on tight timelines with specific growing temperatures, watering and fertilizing regimes which include progressive “potting up” schedules to “finish” the plants off properly before delivery to their destination gardens – Laking Garden, RBG Centre, Hendrie Park, and the Rock Garden.

Occasionally, disappointments and unforeseen circumstances arise; one or more plant “crops” fail, underperform, or for various other reasons are unsuccessful on the propagation bench. Fortunately, our talented and extremely adaptable staff have become adept at substituting surplus plants for those that don’t work out. One such example in the spring of 2019 was a failure of a Fountain Grass variety (Pennisetum) that was replaced by using the ornamental grass, Melinas nerviglumis ‘Savannah’ (Ruby Grass) instead. In the end, Ruby Grass proved to be big hit with our visitors, with staff fielding questions about it all season.