Kill it with fire!!!

[Mushaville]

This is usually my OH's solution to most things but I've pointed out to him that we can't just set fire to all the weeded parts of the garden lol

We are currently trying to expand a path across a very over grown and neglected border, we are digging it over and removing any of the weeds/plants/roots we can, digging it down by about 1.5 foot...so far about a 6ft stretch has taken us a hour and a half, it is riddled with weeds and plant roots!

Obviously the last thing we want to happen is to clear it and then have things trying to come through the block work once it's laid

What can I use to essentially make it a baron wasteland where no plants/weeds/ANYTHING would want to grow?

I feel bad for asking such a thing as a keen new gardener but some parts of the garden are weed and root infestations.

Would normal weedkiller do it or am I looking at ordering something specially online??
Any advice greatly received

[Alison]

Don't worry about killing it all, just use a decent quality weed membrane under your path. No worries with strong weed killer getting where you don't want it that way . Note that although I don't use weed killer on principal I don't actually see that it would be an advantage here anyway.

[Valleyman]

My method would be:

1) Let it grow till mid summer, when the weeds are in full growth
2) Don't let a single weed set seed otherwise the problem will spread everywhere. You could achieve this by strimming regularly
3) Spray Glyphosate on the area
4) Wait two weeks
5) Spray Glyphosate again if anything is still alive or poking through. Make sure everything is dead.
6) Cover with a layer of compacted type-1 and sharp sand
7) Lay blockwork
8) Brush a sand and cement mix into the cracks to prevent future weeds setting seed

It's not quick but you'll have a weed free path that will last for years in good condition. The only things that can really cause problems with this method are Japanese Knotweed and bamboo.

A membrane may also work, but on a narrow area like a path things like bindweed will just send out rhizones and spread the problem laterally rather than kill it.

Whatever you do, don't use fire though. It works on shallow annuals in cracks on paths etc. But deep rooted rhizone weeds and many pernenials will just grow back.