Spring Removal of Giant Hogweed
Mike Cowbrough, Weed Management Field Crops Program Lead

I'm at this Giant Hogweed infestation. It's the first of May and the other reason that this is a perfect time to control Giant Hogweed now is it's only about 30 centimetres tall, we have fairly easy access to the root system and we can get below the crown. Also it's nice weather, it's 15 degrees, I'm not sweating out here wearing my protective clothing. Once we get into July and August this plant grows exponentially to the point that it eventually gets 12 to 15 feet tall. So it's difficult to access the crown root and dig it up, it's hot outside its 30 degrees and muggy and humid.
Giant Hogweed Removal Strategies
Here's a perfect example of where we try to minimize it's impact. We have an agricultural field right behind us, the plant isn't that big, we're going to try three or four different strategies and quite frankly, see how they work.
Mechanical Removal
We're going to try and dig these plants below the crown and remove them that way. So it's just good old sweat and tears physical labour. I want to get as low as I can below the crown. Here's a pretty big plant we got a good 10 centimetres below the soil surface, that's probably where we want to be at.
We dug up below the crown of Giant Hogweed but my suspicion is it's going to keep growing back, so one of the things we're going to try here is putting a physical barrier over top those newly rooted plants, try and keep them below the soil surface and eventually smother them out. So I'm going to take this sheet of plastic, black side up to attract some heat, I'm going to put it over the population that I just dug up, and then I'm going to anchor it down with just some sandbags, and we'll see how well we do at keeping this population at bay.
Chemical Removal
So the next couple of treatments that we do involve herbicides and this is Glyphosate, so it's an approved use for Giant Hogweed, a plant that's poisonous to the touch. All we've done is mixed up a 2% solution so that's 20 mL of the concentrated product with a litre of water. What I'm going to do just to protect myself is I'm going to put on the goggles and the respirator and then I'm going to just spot spray individual plants and be very specific and try and get the product only on the leaf surface and not anywhere else.
Last treatment we're going to do is an example of a wick application, and all a wick is basically a rope or a sponge, something that absorbs a product like round-up and we can use it and dab the plants without having to spray. The nice thing about a wick like this is we got a long shaft that we can reach and get plants that are in odd areas, and we're just trying to cover them with that 2 per cent solution. If you're going to use a product like round-up, an over-the-counter product, to control Giant Hogweed, make sure that there's no rain forecasted for at least 30 or 40 minutes.

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