[ah well]

Hi - 1st post on this wonderful forum

Just wondering if anyone knows what this plant is. Growing in my back garden in a hilly area untended with high grass and lots of dock plants (until it gets strimmed periodically). Seems to grows extremely quickly after being cut to ground level. Also seems to be popping up all over the place as time progresses. The stems are relatively red in colour with large green leaves.

Thanks!

[Sive]

Don't mean to be alarmist, but could it be Japanese Knotweed ?
What does anyone else think ?

[kindredspirit]

Yep, looks like Japanese Knotweed, the most invasive plant of all.

You'll have your work cut out to get rid of that. It takes over completely eventually and kills every other plant.

http://www.steger-lewis.net/aj/knotweedinfo.html

[ah well]

Thanks for that folks - looks like it's Japanese Knotweed alright

The topsoil in that part of the garden came from elsewhere when the place was being landscaped so I suspect that's how this thing arrived.

That particular area has no plants/shrubs in it at all besides wild grass, dock plants and this stuff - effectively growing wild - so it's time for Glyphosate aka Roundup I think and hope for the best

[tippben]

The only way I've found that effectively kills this stuff is to let it grow for a couple of months, then inject the stems with neat glyphosate using a hypodermic syringe (luckily my wife is a nurse- no hanging around in dodgy pubs!). You have to inject the stem itself, not the hollow space inside. DON'T strim it! Every little fragment can become a new plant. It can take several treatments to get rid of it.

[medieval knievel]

i know someone who bought a house which had a back garden which was infested with the stuff. cost her five or six thousand to have it cleared - the soil is treated as a biohazard.

[frengers80]

i remember seeing an programme,maybe countryfile,about one of the sites for the london olympics which was infested with that stuff and they where injecting the stems with round up as mentioned above.I think they now have released a bio control in the uk to try control this along riverbanks/railways etc.

[molly-bronski]

I've spent the past couple of weeks tearing that weed up, didn't realise what it was. It's spreading like wildfire. The garden was a bit neglected last year and it grew to about 5 feet tall.

[inishindie]

The young shoots of this invasive plant are edible and can be made into wine, just substitute rhubarb with knotweed. The idea is to pick small asparagus looking tips from the knotweed plant and make them into wine, puddings, again like you would with rhubarb, either a crumble or a fool. Harvesting between now and May is the best time as the shoots are young and tender.
It's estimated that in the UK alone it would cost £13.5 billion to eradicate the pest and has already cost £70 million to keep it off of the new Olympic site in London so we will have to do our bit to make sure we can keep it in check in Ireland.
Cutting the plant back weakens it and the plants will eventually die off so eating the plant will be a good idea all around. We haven't tried this yet so if you feel brave and do it before us I would be delighted to know how you get on- check the internet for recipes and health and safety tips..
A couple of words of warning though; Knotweed will grow anywhere, even through concrete, asphalt and most importantly through sprays of herbicide. Make sure you gather it from places where you know the soil is clean and chemical free. The other thing will be to burn anything you don't eat. The plant can grow from the tiniest piece left on the ground.

[medieval knievel]

i spotted it in the big herbaceous bed in blessington basin in dublin. will be interested to see how the council deal with it, they maintain that site...

[michael brenock]

spray with Roundup in the Autumn when the leaves are just beginning to turn yellow. The following year it will come up much weaker and repeat the dose the second Autumn. timing is as important as the material. I have helped a client to get rid of it in this way.
michael brenock horticultural advisor (retired)

[inishindie]

You don't work for Monsanto in your spare time do you Michael

http://www.youtube.com/watch?v=xw1irzxDsXc

[walltoall]

I live near Olympic Park and have seen Japanese Knotweed at its most invasive. I'm pleased the tenor of this post has been to underline how difficult it is to eradicate and how important it is to do so. Roundup on yellow leaves in Autumn with a follow in Spring as espoused by Michael Brenock is a tried and trusted trick. As is the hypodermic syringe method of getting the poison into the plant. (We can find any number of them around here.)

Systemic poisons normally work by the sprayed liquid adhering to the surface of a leaf usually due to an element of surficant or sometimes deisel in the mix. The poison is then taken up by osmosis and travels to the heart of the plant where it kills it with kindness by sending its growth pattern haywire. Systemic weed-killer is nasty stuff and I would use it as a last resort unless I'm dealing with Japanes Knotweed and then it is a first choice.

There is more but the bottom line is that something about the structure of the japanes knotweed prevents the poison getting to the heart of things. I am sad to see that this awful plant is in Ireland but I exhort anyone who comes across it to forget all you believe about organic farming when you are dealing with Japanese knotweed. Ends rant............

[michael brenock]

inishindie I do not indeed work for monsanto or have anything to do with them. I was involved with trialling the product way back before the launch and I was impressed by it and it is so safer than Paraquat. Roundup is the only chemical that I use.
michael brenock horticultural advisor (retired)

[inishindie]

Thanks for pointing that out Micheal...

Seems that you have no bother recommending other types of weedkillers to forum members.

http://www.gardenplansireland.com/forum/about4381.html
http://www.gardenplansireland.com/forum/about5015.html

You might think me a bit of a pest, I know that this forum isn't solely an "organic" one, but I think that the use of weedkillers are a quick fix that doesn't really work.

It's the root of the problem that needs looking at. I suppose if people ask what type of weedkiller to use we are likely to give an answer...My hope is that every other angle will be assessed first instead before a toxic solution is offered...That's the only way we can cut toxic chemicals down to a bare minimum or eradicate it...They are leaving a nasty track record behind them both in the gardening and agricultural sectors.

We need to Work with Nature...not against it....Live for diversity and move into a cleaner, more accepting way of gardening.

Just to add though that your advice (on non chemical issues) is extremely educational and exemplary and helpful.....