Japanese Knotweed - Winter Canes

[Tangaroa]

Can anyone tell me if its a good idea to cut Japanese Knotweed canes in the winter?

I have heard this is essential to allow frost to further weaken the rhyzome and to make control work next spring/summer easier as there would not be any dead canes restricting access into the JK stand when injection the stems?

Any thoughts would be appreciated......

[Dogghound]

I have always used (or advised the use of) herbicides, so im not to sure about frost. For herbicide we cut the plant really short then apply. So probably the same occurs with frost, cut it to just above ground level. Also make sure your cuts are clean and its not broke into loads of segments, I would burn the waste vegetation as well as it can regenerate.

[Tangaroa]

Hi Dogghound, thanks for your reply.....

I probably wasn’t clear in my initial post. We have been using herbicide during the growing season and have been administering it using the Stem Injection system. This method appears to have been fairly succesful in killing the stems (in the short term at least).

I kind of assumed that JK wouldn’t be able to re-generate from the dead winter canes? One of the reasons I would like to clear them is to give me better access to any re-growth next year as I found the previous year’s canes were a bit of a nuisance and restricted access within some of the larger stands.

[Dogghound]

Originally Posted by Tangaroa

I kind of assumed that JK wouldn’t be able to re-generate from the dead winter canes? One of the reasons I would like to clear them is to give me better access to any re-growth next year as I found the previous year’s canes were a bit of a nuisance and restricted access within some of the larger stands.

Sorry I see what you mean, no its unlikely to regrow from dead canes from last season (2010), I meant if you were cutting back live canes.

[basquesteve]

Its a terrible weed best of luck

Steve

[tameblackbirds]

I use the dried stems cut into short stems bundled together with string. I then tie them around the garden for insects to hibernate in spiders use them and other insects, A good use for such a problem plant

I have had JK at the bottom of my garden for over 25 years I control the spread by cutting out any new shoots cleanly and leaving to dry. This as worked all these years, the spread as stayed contained.

[Dorts]

From my experienc there are only two ways to control Japanese Knotweed.
One is the persistant use of herbicides during the growing season, or the persistant cutting of all growth at least once a fortnight. Both methods must continue for at least two years for any chance of success.
But don't turn your back or it will be back for sure!
Dorts.

[brendaward]

Don't the department of the environment deal with destroying japanese knotweed. There has been adverts in local papers telling people to leave it too the professionals and numbers to ring if you see it growing in our area. This was about four years ago so has it changed or is it just regional?

[Brocakat]

Originally Posted by Tangaroa

Can anyone tell me if its a good idea to cut Japanese Knotweed canes in the winter?

I have heard this is essential to allow frost to further weaken the rhyzome and to make control work next spring/summer easier as there would not be any dead canes restricting access into the JK stand when injection the stems?

Any thoughts would be appreciated......

The canes in question are simply THAT seasons Herbaceous Growth. Which is now dead & dried.

What their 'usfulness' is in that situation, is for is merely giving some(slight) protection against frost to the (dormant in-winter) growing tips at the top of the rhizomes.

These rhizomes at the base of the dried cans are alive- but dormant. Just waiting for the following April/May when they make their 'Big Push'

But let us not forget that the surrounding soil/growing media around these rhizomes will get as eventually as cold to the same degree, over any period of prolonged frozen conditions. The longer the period of cold, the deeper the
depth of frozen ground. But I've yet to findf a formerly large 'stand' of the stuff now-all-killed-off - becuase of the severity of the cold in any previous given Severe Winter.

Because these plants are frost-hardy to what-seems-to-be "numerous" degrees of frost ( however I do not know the limit of their hardiness)- coupled with our knowledge of the potential depth of their roots - I beleive that the removal of those old canes is-------- pointless.

One either injects the rhizomes with a Herbicide - literally directly with an adaptation of a Sheep 'Drenching' Gun, or sprays the shoots when they have emerged past the point of 0.6 m height . Repeatedly, over the next 3 years !

By Gum it's tough stuff this J.K.

[Brocakat]

Originally Posted by brendaward

Don't the department of the environment deal with destroying japanese knotweed. There has been adverts in local papers telling people to leave it too the professionals and numbers to ring if you see it growing in our area. This was about four years ago so has it changed or is it just regional?

Tell your local Council if you see it on any Parkland, or land under their authority ( like , e.g. 'Council - Housing' land )

Tell your County Council if you see it on any Roadside Verges etc. etc.

Tell the Environment Agency if you see it on Riverbanks.

Al the above use their own qualified Herbicide applicators to treat unwanted vegetation on those areas of land.

J.K. is non-toxic, neither does it case any skin rashes. It's even edible when the young spears are still red.

Farmers, other landowners ( including Home-Owners ) do NOT NEED to use external professional 'Teams' to treat J.K. on their land. However, whether it is economic to treat the plants oneself is a home-accountancy exercise firstly---but remember:-

Home owners can legally use both the active ingredients (ai) Glyphosate and Tripclopyr that are of course available to Professional Teams for Spray application, however I believe the ( professional) injection method to be the most effective at elimination - and to 'tool-up' for utilisation of this method is probablly uneconomic for any individual landowner ( apart from an Estate Manager of a large Country Estate ) -unless the equipment is going to be used year-on year. Yes, it will need treating for the next 3 seasons to ensure a complete kill.