Wildflowers are notoriously difficult to establish. They usually require you to strip an area of turf, having controlled all the weeds, to make sure that you have a sterile seed bed. Wildflowers are very delicate plants and hate competition from weeds or other grasses.
An alternative method is to simply over seed wildflowers into an existing area of grass. This method is well known but is extremely unreliable because grass species such as ryegrass, are very aggressive, leaving wildflowers little room, water and nutrients to get established.
Yellow Rattle (Rhinanthus minor) is a parasitic plant that can help to restrict grass growth. It can be oversown into an existing grass area, and it will start to feed off the plant roots, meaning that the grasses become less dominant, allowing wildflowers to establish more easily.
One thing to note however, is that Yellow Rattle is only an annual, and it will need to be left to flower, so it will set its seed and come back the following year.
The majority of our wildflower mixtures contain Yellow Rattle seeds, but if you want to add extra, or plant it on its own prior to trying to establish a wildflower area, we supply it in small packs.
Best of all, Yellow Rattle is a species that is recommended by the RHS Perfect for Pollinators scheme, which means that you can control you unwanted grasses, and provide a perfect haven for wildlife at the same time.