Unexploded shells, an outbreak of a tree-killing disease in Europe and even pesky Canadian squirrels have failed to defeat Monty McDonald.

McDonald, 72, remains determined to fulfil his dream of building a living memorial of oak trees at Vimy Ridge to honour Canadians who fought there 100 years ago.

“I have done half a billion dollars’ worth of projects and this is the most frustrating,” said McDonald, who used to work in the petrochemical industry.

“More setbacks, more unknowns than any project I have had.”

There have been so many issues that time has run out; The trees won’t be planted in France for the centenary of the battle as first planned.

“But we’ll get it done,” said McDonald firmly. No one who works with him has any doubts.

McDonald and a group of volunteers have grown enough trees to fill a forest, more than 1,000 alone at a nursery in West Flamborough, Ont.

Unfortunately, none of them can be shipped to France and planted near the famous Vimy Memorial, which was the original idea.

So, in one of many “contingency plans” McDonald has been forced to develop, the special “Vimy Oaks” are being shipped to communities across Canada. Orders are coming in from across the country, with many of the trees expected to be planted near cenotaphs or legion halls.

“The trees for Canada program is working out a lot better than the trees for Europe,” McDonald said wryly.

The entire project traces its roots back to a handful of acorns picked up by a Canadian soldier back in 1917.

When the battle at Vimy ended, Leslie Miller surveyed the barren landscape and, with the instinct of a tree farmer, gathered some acorns from a fallen English oak. Miller sent them home to Ontario, where his family planted them.

Years later, they had grown into an impressive stand of trees and Miller named the farm “Vimy Oak.” About that time, Miller hired Monty McDonald to work on the farm and when McDonald’s father died became a mentor to the young man — “like a grandfather” — and one whose memory is still treasured.

The farm is long gone, but some of the trees still stand on a small woodlot next to a church in what is now a suburban area of Toronto. A trail offers visitors a chance to walk among the Vimy Oaks and remember the battle and the fallen.

But when McDonald toured the memorial at Vimy Ridge more than a dozen years ago he was disappointed.

“I didn’t see any oak trees there,” he said.

He immediately thought of the oaks from Vimy on the farm in Canada.

“I thought… wouldn’t it be cool to repatriate them,” he said. “Plant two or three trees.”

He set the idea aside but came back to it in a big way as the 100th anniversary of Vimy Ridge approached.

McDonald’s dream developed. He envisioned 100 carefully planted trees, with a landscaped area were visitors could walk, sit and and contemplate the risks taken and sacrifices made by Leslie Miller’s generation.

The Vimy Foundation offered support and a team of volunteers came together. The project had momentum.

However, at a key moment, the trees in Canada refused to co-operate. When McDonald went to collect acorns from the trees in the fall two years ago, there were almost none to be found.

McDonald built special traps to catch the acorns and protect them from hungry squirrels. He put up plastic owls and even built rubber snakes, hoping that might help.

The harvest, however, was miniscule.

“That year, ten acorns came off the trees,” he said. “I ended up climbing up the trees looking for acorns and there weren’t any.”

With time running out, McDonald came up with a new plan. The oaks were scaled, and the cuttings — called scions — were taken and grafted to rootstock brought in from British Columbia.

It worked, producing about 200 healthy oak trees, still connected genetically to the acorns Leslie Miller collected at Vimy in 1917 — and big enough to be shipped to France for planting.

“Unfortunately, along comes a new pathogen that is ravaging trees in Europe,” said McDonald.

There is fear that Xylella fastidiosa will do huge damage to trees in many countries. So late last year, McDonald was told that, despite all the testing and precautions he had been working on, the Vimy Oaks weren’t going to be allowed into France.

“Here all these trees sitting in Canada and we can’t get them over to France,” said McDonald. “That was the silver bullet that killed us.”

Not quite. McDonald had quietly hatched another of his contingency plans.

Last fall, when he was still hoping the grafted trees would be allowed into France, the Vimy Oaks produced huge quantities of acorns. They rained down faster than squirrels could grab them.

McDonald collected thousands and shipped a few hundred to a nursery near Paris, just in case.

The acorns in France are now sprouting. They aren’t big enough to put in the ground yet, but the ground isn’t ready. A crew is still searching for unexploded ordnance in the area set aside for the trees — another last-minute complication.

McDonald now hopes to get the landscaping work completed and trees planted by Remembrance Day 2018.

“In the space of a 200-year of an oak tree, what’s a year and a half?” he said. “We are going to stick with it.”

He has to, he said. Leslie Miller, the soldier who collected the original acorns and helped him through difficult times would expect him to finish the job.

“You couldn’t give up,” he said. “He wouldn’t let me.”