In late
autumn, when the last of the cabbages have been harvested from the kitchen
garden, the flower borders cut back and cleaned up, and all the spring bulbs
planted, the action at Toronto’s historic Spadina House heads indoors to the
greenhouse.
Spadina’s pretty white greenhouse was built in 1913 by the venerable Lord & Burnham Company of New York. Established in 1856, Lord & Burnham was responsible for some of North America’s most famous glasshouses, such as the Conservatory in San Francisco’s Golden Gate Park (1879) and the magnificent glass-domed Enid A.Haupt Conservatory at the New York Botanical Gardens (1902).
In the early 20th Century,
the Austin family, then owners of Spadina House, would sow seeds of favourite
annuals like sweet pea directly into the soil that filled the tile-bottomed
wooden frames of the greenhouse benches. 
Today,
although the seeds may be grown in plastic flats or peat pots, the greenhouse
still has many roles to play.
Before the first frost, any tender
plants used to decorate the main house’s Victorian-era Palm Room throughout
winter are brought into the greenhouse from their summer sojourn outdoors:
ferns, palms, philodendron, brunfelsia, lantana, bougainvillea, plumbago and a
handsome Fuchsia magellanica, to name a few. Favourite perennials
growing at the limit of their hardiness zone, such as bear’s breech, Acanthus
mollis, are also brought in.
Cuttings of geraniums and other container annuals made by the gardeners
in late summer are grown on in the greenhouse for use the following spring. In
early winter, potted bulbs forced in a below-ground pit outdoors that show good
growth above the soil level are 
brought
into the greenhouse to set their flower buds, then transferred to the main
house in bloom. Finally, after Christmas, the yearly seeding program of annuals
and vegetables begins. In late winter or early spring, many of these young
seedlings are moved out of the greenhouse to an adjacent cold-frame for
“hardening-off” prior to going into the garden in late May.
In order to fine-tune critical night temperatures for various types of plants, the greenhouse features two sections separated by doors. In the “cool section”, daytime temperatures might reach 70F (20C), but at night drop to a cool 55F (12C), the temperature favoured by hardy annual seedlings, spring bulbs, freesias and temperate plants like Martha Washington geraniums. Night temperatures in the “warm section” don’t drop below 65F (17C), making it ideal for tropical orchids, ferns and amaryllis bulbs. To protect plants such as orchids that prefer filtered light rather than direct sunshine, panels of gauzy fabric are suspended from the greenhouse roof.
Toronto’s historic Spadina House was
built in 1866 by the Austin family, who occupied it for four generations before
selling it to the City of Toronto which now operates it as a museum. In the
early 1980s, Spadina’s extensive Victorian and Edwardian gardens were lovingly
and historically restored by the Garden Club of Toronto. Located at 285 Spadina
Road, the museum is open from 12-5 p.m. Tuesday to Sunday. Admission fee
applies. The gardens may be visited during those hours free of charge.
Adapted
from a story that appeared originally at Chapters Online