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I sent this e-mail to the environmental agency and received the answer, both below. I am now even more confused,

Are my concerns unfounded?

This may be of little or no importance, but I thought there was some sort of problem with Japanese knotweed, and looked it up on the internet.

I volunteer at a hospice one day a week, my job is to arrange flowers for areas of the hospice. We receive a lot of floral tributes from various florists, which we dismantle and rearrange.  A lot of the tributes contain Japanese Knotweed , and this has make me question if, by putting it in the household waste, is in fact doing harm to the environment? If this is the case, then maybe we as a country should not be encouraging the use of this plant as a general foliage, used in the Florist industry.

Regards Carol West


Dear Carol,


Thank you for your email regarding the use of Japanese Knotweed in floral arrangements.


Japanese Knotweed is not reportable to the Environment Agency and we have no regulatory powers regarding the management of this weed. The Environmental Protection Act 1990 lists the plant as a 'controlled waste' and it must be disposed of properly. The Environment Agency regulates these activities. It is an offence to plant or cause Japanese knotweed to spread in the wild under the Wildlife and Countryside Act 1981.


The plant is mainly spread through the fly tipping of green waste containing Japanese knotweed and by vehicles transporting contaminated soil and waste between sites. However, if the plant is being spread by the incorrect methods of removal (i.e using a strimmer and spreading the plant) this is reportable to your local police Wildlife Liaison Officer. You can find contact details of your local police station on the UK Police Service website.


Our website has guidance and clear pictures of Japanese Knotweed, if this plant is being used in the floral arrangements as you suspect please contact your local Wildlife Liaison Officer.


hmmmm.  I thought this was a notifyable weed.  

Carol, I share your concerns.  I no longer buy recycled compost from the council for this very reason, viz., that it is likely to contain invasive material.

I was under the impression that jap knotweed needs to be eradicated and this is official thinking.


If you're sure that it's JK Then I would contact the local WLO and discuss.

Over the last year I have seen a lot of harmless plants mis-identified as JK. How sure are you?

Lots of people will be releasing this stuff to tips and I'm surprised florists are supplying it. 

Your local council website should have information on disposal - usually under Recycling, Rubbish and Waste or similar. The stems should go to an approved landfill site and certainly should not go in green waste for composting.

I didn't know that it is used in flower arranging, looks pretty ugly to me!


I'd be surprised if Japanese Knotweed is being used by florists, but of course I may be wrong.

There are lots of different plants from the Persicaria family, some of whom also share the name Knotweed, and many of these are valuable garden plants - I have seen some of these used in floral arrangements.

If you click on this link and scroll down, and then click on the link in Spot the Difference, you will find some of them.



the more I think about it the more unlikely it seems. It would be letting JK loose to colonise private and council compost heaps and land fill sites all over the country. As far as I know that hasn't happened


There is no such thing as a notifiable plant. Human diseases, yes, plants no.


There are injurious weeds which it is an offence to have growing on your land.  Councils should get rid of them from road verges, but they don't.

I suspect Carol is mis-identifying what is in the florists' flowers.


I think the offence is to cause or allow them to spread onto farmland.

Carol, what makes you so sure Japanese knotweed is being used?  

I hope that the stuff is not Japanese Knotweed , I would send some to the RHS , if it is then please don't let this go 

Everything you read on the Internet is true , this stuff is Herendous , I'm on a Housing Ass Board and a couple of years go we spent thousands to get rid of this stuff from a site 


Lot of mis-information on Knotweed on here.

There are no notifiable plants in the UK - The Plant Health Act 1967 legislates for 'problem plants'

The Wildlife and Countryside Act 1981 states that it is an offence to "plant or otherwise cause to grow in the wild" any plant listed in Schedule nine, Part II of the Act. That list includes Japanese Knotweed. You can grow it in your garden but cannot grow it outside of a garden nor put any cuttings into the council recycling etc.

Japanese Knotweed is not difficult to eradiacate if you control it. Assiduously removing shoots kills it. Some people are lazy and let it grow and spread.

If you have Japanese Knotweed then do not send it to the RHS or anyone else. Contact your local authority and ask them for advice.


I think the thought re sending it to the RHS was that there was a possible mis-identification 

Japanese knotweed is extremely resistant to chemicals. ,here in cormwall we have been trying to eradicate it for years.  I noticed a patch where knotweed was supposed to have been eradicated for it now to be appearing with even greater vigour.  This is on council land.  As things stand jap knotweed is winning

I well recall being shown jap knotweed being burned to a crisp yet was starting to shoot again a few months later.  

Leave it......I.e. removing shoots as,they appear......and it will take over.   

If I had any knotweed in my garden I would move.



You have to be a member of the RHS to send them a sample to ID.  Technically sending them a Schedule 9 plant is illegal as it includes 'activities that disturb the vegetation and underlying soil.' A bit cyclical if you want to ID them I know!

It is not an offence to have Schedule 9 plant species growing on your land and there is no legal requirement to control them. Remember that garden favourites like Rhododendrons, Azalea, False Acacia, Gunnera and Virginia Creeper are on the list.


Lion S

It's usually the stems of Japanese knotweed that are used in floral arrangements. Sometimes dried but also fresh stems. (scroll down to "Mysterious Aroid")

Carol, if the arrangements have fresh stems in them, please be careful when disposing of the stems and make sure they can't get composted.

Yes break.  Jap knotweed is unlike any other weed. And even a very small piece can become an immense problem in your garden


Flowerchild, I can't think of anything more irresponsible than that flower arrangement. The  blogger states they are the scourge of the countryside, but unless they are disposed of by burning, then they can spread. I certainly wouldn't have thought twice about being able to dispose of dead flower arrangements in a green bin. There would even be the danger of putting it on the compost heap and spreading it around the garden.

And, as I said before, burning doesn't "do" for them either, at least not in a usual garden burn up.  It was quite eerie to see an apparent piece of charcoal with new shoots showing. will never die