After Thanksgiving, the Experimental Farm Next Door Switches From Pumpkins to Lilac Cuttings

In June 1927, two visitors from Boston's Arnold Arboretum came to the Ornamental Gardens at the Central Experimental Farm to see some lilacs. The botanist Susan Delano McKelvey and herbarium curator Alfred Rehder had heard about new hybrids bred by Isabella Preston. In 1920, Preston had crossed the Nodding Lilac with a hardy species and raised 250 seedlings. McKelvey was impressed enough to give the group its name, Syringa x prestoniae. She named one selection 'Isabella' and another 'W.T. Macoun' after the Dominion Horticulturist who had hired Preston. That account appears in the Friends of the Central Experimental Farm Fall 2026 newsletter, in a piece by Richard Hinchcliff.

Nearly a century later, the same issue explains why those lilacs still exist. Part of the reason is work that happens long after the museum puts away its pumpkins. For anyone living in Dow's Lake or the Civic, the Farm's busiest public weeks are ending now. Its quieter season matters just as much.

The Pumpkin Weekends End on November 1

The Canada Agriculture and Food Museum at 901 Prince of Wales Drive runs its Amazing Autumn Weekends this month. Each weekend has a pumpkin corner where you can pick a pumpkin to take home while supplies last, a Spooky Barn the museum warns may be too scary for some visitors, a Halloween games room and family movies. Everything runs 9:30 a.m. to 4 p.m. and is included with museum admission. The museum's What's On page also lists baling demonstrations.

Science for Tots "Halloween at the farm" is a hands-on program for babies, toddlers, preschoolers and the adults who bring them. It runs as three age-based sessions, and you need to register in advance.

After November 1, the museum keeps its regular hours of 9 a.m. to 5 p.m. every day. It stays open on statutory holidays except December 25 and 26. The barns stay open after the pumpkins are gone. The exhibitions there include The Art of Science, about illustrations by Central Experimental Farm artists, and Cultivating Canadian Ingenuity, about agricultural discovery.

The Tree Tour Is About Your Street

On Sunday, October 18, the Friends of the Farm run their Urban Tree Species tour, led by John Hoogendoorn. It's the event on this fall's calendar most closely tied to the streets around the Farm. The tour covers day-to-day City Forestry work: tree maintenance questions, problems caused by planting the wrong tree in a given site, and foundation issues caused by trees. It also covers Ottawa's efforts to preserve and grow the urban canopy.

The tour starts at the Building 72 parking lot in the Arboretum and goes ahead rain or shine. It's free, but you must register in advance, and parking is limited. The Friends accept donations at the end. If you live a few blocks away, walking over solves the parking problem.

This tour is the latest in a 2026 series. Erik Pohanka led a native tree identification walk in July. Earlier tours were Robert Glendinning's "Spring Flowers at the Experimental Farm," Jacob Miall's "Nature vs. Nature: Inside the Arboretum" and Eric Jones's "Architecture of Trees." The setting is a 35-hectare collection of more than 2,000 varieties suited to this region, according to the Friends of the Farm.

Why the Lilac Rows Run on a Winter Clock

The lilac collection is the clearest example of the Farm's off-season work. Robert Glendinning is the Gardener/Propagator with Agriculture and Agri-Food Canada. In the Fall 2026 newsletter, he writes that the Farm's lilac collection is one of the largest in Canada and may be one of the largest in the world. Some of its cultivars exist nowhere else, and many aren't found anywhere else in North America.

He describes two propagation seasons. He takes cuttings just after the lilacs flower. Grafting material is collected later, from dormant wood. In 2025 the Farm started sharing its rare plants with the International Lilac Society. This past winter, he collected grafting material from a dozen unique cultivars and sent it to Society members, who propagated the plants so other collections can grow them. Glendinning explains the winter timing in the newsletter:

"Dormant twigs in December travel better than leafy stems in June."

The newsletter names several of the rare plants. 'Heavenly Blue' was developed in southern Ontario and, according to the records, exists nowhere else. The Farm has two healthy specimens, and after Glendinning took cuttings last year, there are now nine plants in the nursery. 'Obélisque', a double white introduced in 1894 by Lemoine Nurseries of France, isn't in any other collection, and cuttings were in the propagation bed when he wrote. Glendinning says the Farm currently has 33 different successfully rooted lilac cultivars at various stages of growth. He aims for at least three specimens of each before planting out into the rows and the landscape.

The plants he puts first include cultivars with only one known specimen, Canadian-bred lilacs such as Frank Skinner's 'Asessippi' and 'Sister Justina' from Dropmore, Manitoba, and 'Woodland Blue', bred by a Mississauga nursery that no longer operates. Most of the cultivars bred at the Farm itself are Isabella Preston's, and many of them exist in only one or two other gardens. Among them is a group of early-blooming lilacs she named 'Norah', 'Maureen' and 'Patricia' after W.T. Macoun's daughters.

The Preston lilacs themselves are a long-term recovery project. Hinchcliff writes that George Vorauer of the Friends and Brian Douglas of AAFC began searching in 2001 for Preston lilacs the Ornamental Gardens no longer had. The Royal Botanical Gardens in Burlington supplied 19 of them, and AAFC began planting the Preston Heritage Lilac Collection in 2005. McKelvey had admired these lilacs in 1927 because they bloom late and stretch out the lilac season. Rare cultivars like these are the ones the propagation program is meant to preserve.

What Stays Open, and What's Still Being Scheduled

Agriculture and Agri-Food Canada lists the Dominion Arboretum, the Ornamental Gardens and the Fletcher Wildlife Garden as open every day and free. Fletcher, near 865 Prince of Wales Drive, is a wildlife habitat restored by volunteers. A few items on the late-fall calendar are confirmed, and others are still in progress:

• October 25: The Ottawa Field-Naturalists' Club calendar on its Fletcher Wildlife Garden page lists an OWSL seed collecting and packaging session. The entry doesn't give a venue.
• November 21: Dr. Wen Chen, an AAFC research scientist, presents "The Farm's Hidden Network: How Microbial Allies and Invisible Invaders Shape Plant Health" at 2 p.m. in the Neatby Salon, 960 Carling Avenue. The talk is part of the Friends' 2026 Speakers Series.
• Holiday Wreath Making Workshops: The Friends say dates are still to come. Their free monthly e-bulletin, Farm Notes, is where announcements appear.
• A volunteer pergola: The Friends plan a new pergola at the south end of the Heritage Rose Garden, dedicated to their volunteers to mark the United Nations International Volunteer Year 2026. It still needs approval from AAFC.

The museum's seasonal weekends wrap up on November 1. The Friends' talks run later than that, and the lilac propagation work described in the newsletter carries on through the dormant months.

Living a short walk from a 35-hectare arboretum and one of Canada's largest lilac collections is part of what a home near the Farm offers, and it's hard to capture in a listing. If you own near the Farm and want to know how buyers are valuing that this season, The Zak Green Team can prepare a personalized market valuation.