Green roof maintenance

High nutrient levels in the substrate can lead to the vegetation on a green roof being dominated by grasses. To tackle this it is necessary to regularly cut the grass in order to remove nutrients. To do this we use an Austrian Scythe, purchased from Simon Fairlie
http://www.thescytheshop.co.uk/

We have also planted yellow rattle, a plant which can be found in ancient hay meadows. It is parasitic, deriving all of its nutrients from the roots of the grasses. This weakens the grasses and allows wild flowers to grow. Emorsgate seeds have produced a useful summary: http://wildseed.co.uk/page/using-yellow-rattle-to-increase-species-diversity