Canadian-Grown Sweet Chestnuts Are Decades Off, But Heartnuts Commercially Grown Here, Are Possible Soon!
by Art Drysdale
by Art Drysdale


Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at

August 11, 2000

Most Canadians, at least those east of the B.C./Alberta border, not only cannot recognize a sweet chestnut (Castanea dentata) tree, but know little about them. Though not even closely related to the well-known horse-chestnut (Aesculus hippocastanum) [i.e. not in the same plant family], the fruit husks of the two are somewhat similar. The disease chestnut blight (Endothia parasitica) was introduced to eastern North America in the early 1900s (likely in 1904) and it spread through the sweet chestnut trees by the 1920s. By the 1930s, virtually all in eastern Canada were dead. The tree does reproduce by stump sprouts (suckers from the roots) and generally trees appearing dead may often produce such sprouts, They will grow for a number of years, achieving up to 3 metres in height, but succumb to the blight often before producing any quantity of nuts. Thus, my opening statement, folks in Canada basically don’t know the tree at all.

There are stands and individual specimens of a reasonable size, producing nuts, located in various parts of Ontario. It would appear that if they are established using shoots from non-blight-infected trees, in areas where the blight did not appear (e.g. in the Ottawa area where there were no trees growing when the blight hit, thus no blight remains) it has been possible to establish a reasonable stand of these beautiful trees.

A new group has been formed to protect the gene pool of this tree in Canada. The Canadian Chestnut Council has as its object the development of resistant cultivars of the tree, and to maintain the gene pool of existing trees until more advanced work on gene manipulation can be done to breed cultivars that are completely resistant to the blight. The group is headed by Dr. Colin McKeen, of Orangeville, Ontario. He may be contacted at (519) 941-9513.

Meanwhile, still on the nut tree scene, SONG, the Society of Ontario Nut Growers, an active group of nut tree enthusiasts, has announced that a number of its members, under the umbrella of SONG, will be pursuing the establishment of groves of the heartnut tree (Juglans cordiformis). This is not a new tree to Ontario (and, sorry, not a native) but one that has long been recognized as an excellent eating nut, as well as a good specimen tree into areas even as cold as zone 4b (Campbellton, N.B., Québec City and Trois Rivières, Québec, Pembroke and Sault Ste. Marie, Ontario).

SONG members, particularly Ernie Grimo, Earnest Grimo Nursery (905-935-9773) and Doug Campbell, Campberry Farm (905-262-4927) both of Niagara-on-the-Lake, have about a half dozen selected grafted heartnut cultivars they are convinced will make excellent commercial nut grove trees. Planted in the last 2-3 years, there are already small groves of these trees ranging in size up to 1.6 hectare (3-4 acres) located in fields almost from Windsor to Kingston.

You might wonder at the practicality of introducing a new agricultural commodity when many commodity producers are having a tough time. The SONG members tell me they are confident that this venture, properly marketed, can work. This is confirmed by two friends in the retail business both of whom specialize in selling locally grown produce. Bill Redelmeier, owner of Southbrook Farms and Winery in Richmond Hill, and Grant Bailey, owner of Bailey’s Farm and Country Market, Caledon, both agreed that this could be a niche item that would indeed sell well.

Heartnuts begin to produce two or three years after planting (typical grafted trees are 60-90 cm [2-3’] high at planting) and should begin producing a commercially viable crop in six to eight years. The trees grow to a height of 8-12 m (25-40’) and reach a spread of 12-15 m (40-50’). They are resistant to the annoying walnut blight, but in some areas, some years, may have a percentage of their nuts attacked by a weevil (Curculio carytrypes and C. sayi). Doug Campbell tells me little or now spraying for insects or disease is anticipated.

Price of the grafted trees is approximately $15 for the 75-90 cm size, and for gardeners just wanting to plant one tree for a small crop of nuts for household consumption, please note that you really should plant at least two trees to assure proper pollination. Ernie Grimo pointed out he was fairly certain that though heartnuts can be grown into zone 5 (and 4b), the grafted trees (most grafts would be put on regular heartnut, butternut [Juglans cinerea] or even black walnut [Juglans nigra]) would probably not be a success in the colder zones. Gardeners in those zones, he said, would be better planting seedling trees.

Just how easy is to grow these trees? I guess Doug Campbell summed it up best when he said, “the heartnut is about as difficult to grow in southern Ontario as the silver maple!”

An interesting point about the heartnut is that some of the older varieties were very difficult to crack open, and once they were open, it was often hard to remove the “meat” of the nut from the shell. The cracking has now been solved with the newer cultivars—they crack open easily. And, the “meat” seems to drop out of the new cultivars quite easily.

Ernie Grimo told me he had recently returned from Texas from whence he brought back some equipment used in the commercial production of other, more exotic nuts. His feeling is that this machinery can be adapted for use on heartnuts, once commercial production is actually underway.

By the way, did you know that with most commercially produced nuts, about 20 percent of the production goes to fresh sale, and 80 percent to packaged shelled kernels? Doug Campbell thinks a similar percentage will apply to the heartnuts once they are in production. One advantage that the heartnuts will have, he tells me, is that they have a long keeping time or shelf life. Whereas most nuts can only be kept about a year before they go stale, heartnuts will actually keep for at least two years before any staleness sets in--and, that’s storing them at regular room temperature and humidity. This allows a considerable degree of flexibility for new growers—keep the unshelled nuts for fresh sale for a year or more, and then if they haven’t sold, shell them and package them for sale that way.

If you’re interested in general information about growing nut trees, you should join SONG. To do so, call the president, Christopher Cunliffe, or his wife, Marylinda. They are in Mississauga—905-270-7890.

Art Drysdale is seen hourly every day on Canada’s Weather Network at 23 minutes after each hour, and heard Saturdays from 9 to 11 am, with a live two-hour radio broadcast on Toronto's TALK640 (640 on the AM dial).

Art C. Drysdale 6 Nesbitt Drive Toronto, Ontario M4W 2G3 416-968-5910 (Voice) 416-968-2092 (Fax)

Art's garden hints are again on Canada's Weather Network daily, every hour at 23 minutes past the hour (except in Toronto between 6 and 9 AM). Please check them out!

  • New Eden
  • Kids Garden
  • Plant a Row Grow a Row