Nova Scotia

Some people are tackling 'Godzilla' of weeds with knife and fork

Nova Scotians are harvesting the highly invasive Japanese knotweed for use in pies, ice cream and cider.

Japanese knotweed can be used as a substitute for rhubarb

While it may be considered an invasive species, there are those in Nova Scotia who are using Japanese knotweed in everything from cider to pies. (Craig Chivers/CBC)

It's known as one of the most invasive species in the world. For some Nova Scotians, it's also known as dinner.

Since it was introduced to North America as an ornamental plant in the 1800s, Japanese knotweed has swept across the continent, displacing native species and damaging infrastructure. 

But Nova Scotians are harvesting knotweed for use in pies, ice cream and cider, and say that it's a "highly useful" plant despite its well-deserved reputation as a noxious weed.

The plant is so pernicious it can push through concrete and asphalt. (

"It has a wonderful rhubarb-like flavour. In fact, I would describe it as a bit better than rhubarb," said Cliff Seruntine, who teaches classes on foraging in Nova Scotia. 

As an invasive species, knotweed can change entire environments. 

Doug van Hemessen, Nova Scotia stewardship co-ordinator for the Nature Conservancy of Canada, said that because knotweed grows in such dense thickets, it crowds out native plants. 

"Once knotweed gets established in any particular area, it does tend to spread very rapidly. So if it gets into places where you don't really want it, then that's a problem, and it is very difficult to eradicate."

Van Hemessen said that one of the reasons that knotweed is so difficult to control is because it can sprout from a tiny piece of stalk or root. 

If left unchecked, knotweed can break through sidewalks and concrete foundations. 

A bottle of Stone Poste Cider's knotweed cider. The label features its scientific name, Fallopia japonica.

Removing the root system is the best way to control knotweed, but with roots that can spread up to seven metres out from the plant and two metres deep, that can be difficult. 

Similar to rhubarb

In the spirit of making the best of a bad situation, some Nova Scotians are putting knotweed's fruitfulness to a more productive use. 

"You can get so much of it so fast, it's such a prolific producer," said Seruntine. "We use the stalks themselves. Up until they're about [40 centimetres] tall, we use them as a tart asparagus." 

Seruntine said when the stalks are taller and start to hollow out, they develop a taste and texture similar to rhubarb. 

Japanese knotweed has a strong stem that's notched like bamboo and can grow several metres tall. (CBC)

After it's harvested, Seruntine said, "You have to boil it and drain off the water … and then [mash] it."

It creates something like a rhubarb substitute which he and his wife use in desserts like strawberry knotweed pie and knotweed ice cream.

Seruntine forages knotweed from the abundant patches growing wild in Nova Scotia. He said he's careful not to drop any pieces when doing so that could propagate the plant.

'It's one of my best sellers'

Richard Armstrong, who produces cider under the name Stone Poste Cidery, said that knotweed cider has proven surprisingly popular, even among people familiar with the plant's reputation.

"Most people were amazed to know I'm actually doing something with it," said Armstrong, who notes the knotweed cider is one of his best sellers.

Armstrong said he got the idea after noticing stands of knotweed growing along the side of the road. 

"Once I identified it and found out it was edible, I just gathered some up … asked my wife to make a pie of it … and I could've sworn it was a rhubarb pie. I knew you could make cider out of rhubarb, so I figured, why not knotweed cider?"

Harvesting knotweed may not reduce its spread, although thorough and persistent cutting, over several years, can be effective. 

But Armstrong said given how difficult knotweed is to eradicate, any strategy that harnesses its better qualities makes sense. 

"Like the internet says: if you can't beat it, eat it." 

Read more stories at CBC Nova Scotia