In reply to Timmd:
> Yellow Rattle is ment to be a good flowering species to combat grasses with, It's a 'carnivorous' species which targets grasses and is sometimes used to help new wildflower meadows to become established.
Yellow rattle's a funny one: it's parasitic in some respects, so does best where it can suck the life out of grass. But it has real problems with tough grass like rye or couch, and does better with old-fashioned leys like meadow and fescue. Plus, as a parasite it is, by definition, suited to poorer soils - it wouldn't need to feed off other plants otherwise. Meadow grasses on poor soil are more amenable to colonisation by wildflowers in the first place. Many gardens lawns are rye-heavy, for its resistance to wear, and laid on decent soils, often boosted with 'weed'n'feed' products. So rattle often disappears without trace in domestic settings. It also takes 2-3 years to really exert a big effect - so that roof garden would still need some attention.
Our next door farmer is looking to retire, build a house on the field next to our house (with our full support) and establish a wildflower meadow. Given that I previously tried to buy the field off him at huge cost to turn it into a meadow, I'm pretty happy about this
. What 'we're' going to do is plant rattle, leave cows on it over winter to really poach the ground and then see what happens. Apart from summer grazing, it's not been fertilized for a couple of years, so should stand a chance of establishing.
On the other hand, as someone who's participated in arable farming on a large scale - as in thousands of hectares - I'm not sure your faith in industrial use of herbicides is *always* justified. I've also seen a number of dog and cat patients with neuro symptoms consistent with herbicide exposure, although thankfully this has receded greatly in the last 10-20 years.