How Yellow-rattle Helps

We have been planting seeds this autumn and winter to improve biodiversity in our local nature area. Our baseline survey showed that there were at least 70 species of native British wildflowers already established there. This number does not include the flowers of the grasses and trees. So far we have introduced another 20 species either as plants or seeds. We do not know how well these will survive and grow but we are prepared to repeat the sowing in Spring and Autumn until we achieve success.

Improving a public space like ours, rather than a private garden, means that we have fewer controls available to protect the small plants and germinating seeds. They are vulnerable to adverse weather conditions; foraging birds, mammals, and invertebrates; inadvertent foot fall; and accidental and deliberate damage through misappropriate behaviour. In addition, the new plants will have to withstand intense competition from the old growth plants such as the many tall-growing grasses.

Prior to sowing, we have cut down small areas of the vegetation to near ground level, and scarified the exposed soil. Then we have scattered the seeds and tamped them down so that each seed is in close contact with the earth. Grass roots remain beneath the ground but all the seeding includes the useful hemi-parasitic plant yellow-rattle (Rhinanthus minor). This plant partially feeds on the grasses and so weakens their growth and height. This allows smaller native flowers to flourish.

The British Ecological Society has released an informative video about the usefulness of growing yellow-rattle, and also the potential disadvantages. As far as we know, Charlton Down Nature Area does not provide a home for any rare plants and therefore it is unlikely that it will be adversely affected by sowing yellow-rattle. It is only being used as an aid to the survival of new species in areas where they would be adversely affected by competition for nutrients by the grasses.

Yellow-rattle is already well established in the central area of the Nature Area (Zone 3) where a variety of wildflowers bloom every summer. However, the majority of the site is less biodiverse and is dominated by grasses, nettles, cow parsley, and hogweed. These are the areas that we want to introduce other plants that commonly grow in and around our village but have so far not colonised the Nature Area.