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Mark Wileman

Knotweed and other Invasive Species Reports/Removal

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Does anyone do invasive species works?

 

Other than the relevant PA units, what sort of training is required to deal with invasive species? In terms of survey, is there a whole lot more to it than just identifying it's presence/absence, I assume plants like knotweed don't have the same predictable root structures as trees?

 

I'm hearing a lot recently about knotweed and there aren't many people dealing with it near me, mostly nation wide companies coming into the area. White transit full of bin bags, 2 litres of glysophate and a picture of some knotweed and I'm good to go right?!

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Depends on how extensively you intended on surveying/reporting. Crucially it will depend on how valid your report is and if it indemnifies your client against future costs etc.

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The thing about knotweed eradication is that a guarantee is required by builders.  Means repeat visits and a performance bond. That's why they price so high. Also duty of care/waste transfer etc.  Tips charge the earth as they have to open up a special deep hole.

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Personally would not use glyphosate with knotweed, don’t quote me but the ratio is something like 5:1 to be really effective so it becomes as costly as using a chemical more suited. We use icade, before that we used Tordon 22k however when it’s license ran out it didn’t get renewed, kind of a theme with chemicals. Also in large clumps you’ll need repeat visits in first season and your guarantee should last 3 years so potential of more chemical to be used if you get bits through in year 2 or 3. 

 

Its ta very hard to guarantee also as if it’s been disturbed in the last few years chances are rhizomes could have snapped under ground and only show years later. 

 

A sure way is to dig and dump again don’t quote me I’m working from the top of my head hear but I think it’s 7 metres in every direction from the knotweed so you remove a hell of a lot of earth and it has to be inspected on removal and the cost to get rid is extortionate soooooo all options add up to £££. 

Edited by WesD

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12 minutes ago, WesD said:

Personally would not use glyphosate with knotweed, don’t quote me but the ratio is something like 5:1 to be really effective so it becomes as costly as using a chemical more suited. We use icade, before that we used Tordon 22k however when it’s license ran out it didn’t get renewed, kind of a theme with chemicals. Also in large clumps you’ll need repeat visits in first season and your guarantee should last 3 years so potential of more chemical to be used if you get bits through in year 2 or 3. 

 

Its ta very hard to guarantee also as if it’s been disturbed in the last few years chances are rhizomes could have snapped under ground and only show years later. 

 

A sure way is to dig and dump again don’t quote me I’m working from the top of my head hear but I think it’s 7 metres in every direction from the knotweed so you remove a hell of a lot of earth and it has to be inspected on removal and the cost to get rid is extortionate soooooo all options add up to £££. 

That's getting on 250 m3 of soil

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I was kidding about the glyphosate :001_rolleyes: I see there are some courses you can do with companies that are supported by the Institute of Chartered Surveyors. In terms of guarantee, if you stuck to the system of work approved by "whoeveritis" then wouldn't that be enough to satisfy builders/banks? Similar I guess to diagnosing a tree in perfect health and it shedding a limb 6 months later due to the "nature factor"?

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Where I work we have a few lad qualified on spraying weedkiller's me being one of them just a 2 day course nothing extravagant.

 

We use an industrial roundup just spraying the usual places roadsides, stoned/ gravelled areas, around obstacles that would normally require strimming ect.

 

Last year I had to walk the whole site (360 acre) and report on any of these 3 invasive species of plants within the site :

Japanese knotweed

Himalayan balsam

Rosa rugosa

 

I done so and we had quite a lot of each species. My employer (MOD) then payed a national contractor who come from the Midlands I believe to come for the next 5 years and spray these areas with of all things the exact same industrial roundup as we use... It done the trick as now after 2 and a bit years most areas are now clear.

 

The only difference is on one of the plantations of knotweed they injected it straight into the stem of the plant.

 

 

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The easy way with knotweed is stem injection @ 2ml neat per stem then follow up the next year with foller spraying new operators need the stem injection part of the certs nptc stem injectors are around £250

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9 hours ago, WesD said:

Personally would not use glyphosate with knotweed, don’t quote me but the ratio is something like 5:1 to be really effective so it becomes as costly as using a chemical more suited. We use icade, before that we used Tordon 22k however when it’s license ran out it didn’t get renewed, kind of a theme with chemicals. Also in large clumps you’ll need repeat visits in first season and your guarantee should last 3 years so potential of more chemical to be used if you get bits through in year 2 or 3. 

 

Its ta very hard to guarantee also as if it’s been disturbed in the last few years chances are rhizomes could have snapped under ground and only show years later. 

 

A sure way is to dig and dump again don’t quote me I’m working from the top of my head hear but I think it’s 7 metres in every direction from the knotweed so you remove a hell of a lot of earth and it has to be inspected on removal and the cost to get rid is extortionate soooooo all options add up to £££. 

I thought that I'd read that the guarantees were 25 years! Not sure how anyone can guarantee that it won't turn up again for that timespan.

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