Japaneese knotweed - if I inject weed killer directly into the stem, will it be harmful to the veg growing in the same bed?

[IlanaK]

Everyone has said that the best way to get rid of it is to inject weekkiller directly into the stem. I can't spray it as it is in my vegetable bed (I will have to kill my gardener, but that is a whole other story!). So,will it leach out of the plant into the soil if I inject? I feed the veg to my kids so don't want to risk it!

ANyone?

I don't know about injecting, but when DH has painted the leaves of JK it has killed plants nearby - I presume the root system of the JK carries it into the soil.

Depends on the weedkiller. If you use one based on glyphosate then it does not get into the soil. Good luck! JK is nasty stuff to shift.

That is what I was worried about. I can't risk it in the veg beds then.

but glyphosate is normally what is recommended to use on knotweed - so could inject that into the stem and not have a problem

But if painting the leaves with it kills nearby plants then it must be getting from the roots to the soil. So injecting it into the stem would be the same.

Even the weedkillers that claim to kill JK don't really do so very thoroughly . The only reliable method is digging up the roots and burning them.

JumpedUp, it probably dripped off the JK leaves and ontonearby plants. When I have had to treat weeds that grow over plants I want to save I covered the good plants with sveral layers of newspaper with only the weed above the paper. Left the paper for a few hours until the weed was perfectly dry, then carefully lifted paper away and binned it.

I thought JK needed completely digging out not just weed killing. It can grow back from a piece of root the size of a thumb nail. I think you might well have to notify the council if you find it. It will grow rapidly and will grow through concrete. If it's found on a building plot it costs thousands to get rid off.

You need to be very careful with JK, as it is an offence to spread it. Guidelines and further clickies here.