Yellow Rattle

Yellow Rattle is a ‘grassland’ annual, it’s popularity is due to it’s ability to stop grass and other species from growing. Sometime called Hay Rattle, this small, wildflower species is named because after flowering the seeds in it’s seed-head ‘shake and rattles’ in the breeze.

Best sown fresh as the seed has a short shelf life, Rattle seeds need spells of cold and thaw, to break its seed dormancy, it’s best sown from late August to November. It will germinate in March, later if wet and cold. We cold treat the unsown autumn seed in winter/spring, if sown early in Jan-Feb-March we get less germination and smaller plants.

So much has been written about this species, than its nearly better to list what it cannot do. such as kill Scutch grass.
Rattle cannot make a meadow grow to an even height, as some grass always escapes Yellow Rattle parasitic or heme-parsitic action of taking water, sugars and nutrients from grass, clovers and other meadow species.
Rattle likes to grow in groups and it is in close growing groups that it develops the ability to reduce the growth of grass as more roots from more plants attach and feed off each grass plant
Think about it, if Yellow Rattle dominates and controls your grass, all other species will be reduced as well. It gets worse, the rattle if not managed can take over your entire meadow, leaving it short on species and looking very brown and died off during most of late summer (not something other wildflower sellers will tell you, that’s because most others don’t focus on helping you to achieve great meadows).

Anyway, Nor will Rhinanthus minor or Yellow Rattle control nettles, dock, bindweed or any other rudimentary species of vigorous weed or plant.
So whats all the fuss about Yellow Rattle? It works, especially on old, worn-out finer grasses, where with in a few years the growth of grass is reduced over much but not all of a meadow. Rattle, keeping the grass growth low has some advantages
Allows other species to compete with grass and clovers