Growing Meadows With Yellow Rattle, Rhinanthus minor Is Easy, Reduces Grass Competition & Lets Wildflowers Flourish

Yellow Rattle, Rhinanthus minor, seedling in a grass sward
Yellow Rattle, Rhinanthus minor, seedling in a grass sward

Yellow Rattle, Rhinanthus minor is an annual, herbaceous, hemi-parasitic plant, often referred to as meadow-makers helper. It’s an invaluable plant if you want to create a biodiverse wildflower meadow as it smothers rank grasses, leaving the yellow rattle and other flowering plants room to grow.

Being an annual it completes its life in one year but continues year after year if allowed to set and shed seed.

And, as the name suggests, the flowers are yellow. They are small, being just 13-15 mm across. The seed pod, when mature, holds the seed loosely. When shaken the seeds rattle, hence the name.

As well as having the ability to reduce rank grass growth Yellow Rattle is claimed to have medicinal value. In 1625 Nicholas Culpeper attributed it as being “good for colds or dimness of sight”.

How To Sow Yellow Rattle, Rhinanthus minor, In New & Existing Meadows

As I write this article its April 2nd and the Yellow Rattle I sowed into my “lawn” last autumn has germinated and is growing well. My “lawn” is well on its way to becoming a wildflower meadow, having been converted two years ago. However within months of deciding to convert our lawn to a wildflower meadow our builders used it for a skip, mobile toilet, storage and cement mixing area! Last year a lot of the meadow seeded plants we had sown in year one returned and did well. However the grass was rank and smothered the smaller species.

Last autumn I cut, allowed to dry in situ, and then removed the long grass. Then I sprinkled Yellow Rattle, Rhinanthus minor over the sward. I didn’t rake or scarify and I didn’t stamp it in as many people advocate. I reasoned that in nature the seed drops from the mature dry flower, lands on the soil and has to get on with it.

My rationale seems to have worked as  I can now see a lot of Yellow rattle seedlings growing amongst the grass.

If I were going to sow a new wildflower meadow I’d do so in the autumn and just include the Yellow Rattle in the seed mix. I’d treat it just as any other wildflower. In other words I’d neglect it!

One point to remember is that Yellow Rattle has a reputation for the seed having a short shelf life. It needs to be sown within a few weeks of being harvested to ensure the best chance of it germinating.

I’m a firm believer that we should interfere as little as possible. Let nature do what it’s been doing for millennia. It’s had plenty of practice and left to its own devices does it very well.

Growing Rhinanthus minor in Subsequent Years

Subsequent to sowing the Yellow Rattle should self sow thereafter. Provided, that is, that it is given time to flower and set seed that are ready for seed dispersal. Cutting the crop too early will prevent mature seeds seeding the area.

How Does Yellow Rattle, Rhinanthus minor, Reduce Competitive Grass Growth?

Yellow Rattle germinates in the spring and, as its roots develop, they seek out the roots of other plants, especially grasses and sometimes legumes. On finding the hosts’ roots they are penetrated by the Yellow Rattle’s haustoria (modified roots) and the Yellow Rattle start to draw moisture and nutrients from them. This can reduce growth in some host species by as much as 60%. Where the suppressed host plants are less vigorous wildflowers can gain a foothold.

It is worth noting that Rhinanthus minor is a semi-parasite. It is a facultative parasite.  This means it doesn’t have to be parasitic to survive. It can survive without other plants. In this case it is likely to be a rather stunted plant. Where it can parasitise other plants, and it seems to prefer Poaceae grasses and Fabaceae (legumes), it will grow into more robust specimens.

Note: All parasitic plants have modified roots, called haustoria, which penetrate the host plant, connecting them to the conductive system – either the xylem, the phloem, or both.


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