The Globe and Mail: At Toronto’s Allan Gardens, the newly restored Palm House frames a big, bright sky

The restored Palm House at Allan Gardens in Toronto. Dave LeBlanc/The Globe and Mail

By: Dave LeBlanc

Last week, I looked up at the big, bright Toronto sky through what had to be 5,000 panes of glass in the big dome atop the Palm House at Allan Gardens.

“It’s about 1,200,” corrected Myles Tompkins, a project manager with Heritage Restoration Inc., with a smile. “Every single one is a little different; you can’t really tell [with] the naked eye, but that side of the dome is four inches lower than this side – it settled over the years – in theory it should have been symmetrical but, in the end, it wasn’t at all.”

Maybe that’s why the dome atop city architect Robert McCallum’s 1909 – 1910 Palm House (160 Gerrard St. E.) is deceiving. Or maybe all of those photons were making me sun-drunk. Either way, it’s a glorious result for an equally glorious building, which enjoyed a ribbon-cutting on May 14.

A building which, before the full restoration, was presenting as shabby. Before the restoration, there was an event with horticulture experts from around the world, recalls Michael McClelland, founder and chair of volunteer organization Friends of Allan Gardens. It rained and everyone inside the Palm House was drenched. “It was like, ‘Hello, hello, you need to fix this,’” said Mr. McClelland.

“And staff would come in in the morning and find a pane of glass on the floor,” added architect David Eckler.

Surprisingly, even in these tough times for the city’s budget, it “stepped up,” continued Mr. McClelland, and paid for “really excellent work.”

In addition to Mr. Tompkins and HRI, heritage consultants/architects AREA (Architects Rasch Eckler Associates Ltd.) and Zeidler Architecture were tasked with the work. And it wasn’t just a gaggle of glass that was replaced. The building’s original entrance, which was removed in the late-1920s (according to author and historian Doug Taylor), was painstakingly recreated using original drawings, and then reinstalled. That meant carving new sandstone sourced from the same quarry, which allowed the “1909” to return to pride-of-place over the main doors.

The original entrance is useful for a couple of reasons, according to Mr. Eckler. It serves as a reception area, for one. “But also there needs to be, every so often, a cherry-picker that rolls through for servicing.” That means the new doors are wider than the originals, but still sport the Union Jack sash pattern on the transom windows above.

“Like many cities in North America, they said they want their own Palm House like the original one in Kew Gardens in London [England], and so New York has one, Toronto had to have one too,” continued Mr. Eckler, “so it became a very British-oriented design.”

In addition to stone and glass, the team had to deal with the restoration of original iron and steel; in some places new plates have been welded onto old for reinforcement. And even metal that was in good order was sandblasted, rustproofed, and repainted. Woodwork was retained where possible, and recreated where needed.

Which means all is now shipshape. Even the way temperature is handled, said Zeidler’s Matthew Firestone. Before the restoration, it would be unbearably hot under the dome. “Right now, it’s actually kind of temperate,” said Mr. Firestone.

Good news for wedding party mascara or the brows of nervous botanists giving speeches. But how to achieve it? First, install a whisper-quiet, made-for-greenhouses HVAC system by Priva. Second, ensure the tunnels underneath the new polished concrete floor are bringing in cool air while clerestory windows exhaust the hot, stale air up above. Finally, tint the dome’s glass using frit, a ceramic enamel, on the south side to partially block the intense summer sun.

Historically, sun-blocking was achieved via calcium carbonate powder or liquids, which, when applied with a glue component, steadfastly clung to the glass unless blasted away with a pressure-washer (you can still see this on the low-rise greenhouses beside Palm House).

The construction of the whole thing started with the donation of family land to the Toronto Horticultural Society by George Allan, the horticulture-loving 11th mayor of Toronto (1822 – 1901). He never saw this Palm House, only a previous incarnation that burned to the ground in 1902. But if his ghost walked through, would he first admire the seamless work that marries new with old, or wonder why there are less plants in the Palm House than before?

Mr. McClelland, hopefully, would be there to reassure him it’s not for lack of space. Instead, it’s to enable using the Palm House specifically, and the other greenhouses and grounds in general, to Torontonians seeking a space for salons, concerts, art shows, town halls, TED Talks, or what-have-you: “They were used for everything, because there was no Massey Hall; Oscar Wilde, on his trip through Canada, spoke at Allan Gardens–all kinds of amazing stuff happened here,” Mr. McClelland said.

He might also show Mr. Allan (and his father William, who first acquired the land and named his estate Moss Park) a booklet, “Growing with the City,” which Friends of Allan Gardens published in Nov. 2023. Flipping to pg. 44 and 45, the father and son might gasp at plans for a “Link Building,” which, as visualized by Baird Sampson Neuert, would occupy the space behind the Palm House all the way to the furthest greenhouses while also enclosing the Boiler House. The arid collection would double in size, there could be a “fruit and spices” collection, Indigenous landscapes, and maybe even a café or restaurant.

At this, the Allans would likely look up at the big Toronto sky, and then nod and smile.