Screen to deter briars, nettles, brambles

Thankfully living in the country side, mega problem. Site directly in front of our house overgrown with rushes, briars, grasses, seeding into our place. Just a stronger version of chickenwire, separating the boundaries. Money is non existant in relation to getting 'pros' in. Any suggestions what to plant to create a screen that can deter these things from invading. Desperate here.

Bamboo? It can get quite high, not too dense and very pleasing to listen to it's rustling in the wind. Select one with care as they can get a it out of hand; but they will grow quite quickly and assist in stopping the weed seeds from flying into your plot. Othewise ask the owner of the strip of land if he or you could possibly mow the weeds before they set their seeds to the wind.

escolonia is very tough fast growing and lovely in flower,easy to grow from slips.an ideal screen.

Yes, I would also recommend the escallonia, see here.

I have my whole site surrounded with it and it has gorgeous pink blossoms throughout much of the summer. Perhaps you should consider putting up some sort of temporary fencing or windbreak material to shelter the young plants while they grow.