weeds and ornamental grasses

[WildBergamot]

Can I use lawn weedkiller on ornamental grasses to kill weeds growing through them?

[Clanad]

Probably not very successfully. Although some weed killers are advertised to attack only broad leafed plants, most weed killer will at least damage ornamental grasses if not kill it...

[heathfield]

A very interesting question! So much so that I've just phoned Scott's (who manufacture lawn 'weed & feed' under various names, like Levington, Evergreen, B&Q, etc, and put the question to them.
Their answer is that ornamental grasses will definitely not be harmed by their 'weed and feed' products.

[WildBergamot]

Oh dear, two opposing answers. I think, since heathfield has gone to the trouble of phoning Scotts (thanks heathfield), I'll have to go with his/her answer. Sorry Clanad. I'll try it out on a small area and if it goes pear-shaped I'll not have lost too much.