A rattling good tale

When it comes to creating a meadow you need allies, and they don’t come much more reliable than yellow rattle.  Rhinanthus minor, to roll out the scientific name, is one of those plants, like kidney vetch, red clover and common knapweed, which is a staple of meadows and an absolute boon for pollinators. And in the case of yellow rattle’s its value extends beyond nectar and pollen.

Now if I told you yellow rattle is a parasite you might recoil, but you should resist; not all parasites are bad news.  Yellow rattle is a point in case.

Yellow rattle is what botanists refer to as a hemiparasitic plant. The ‘charge’ laid at its door is that it steals nutrients from surrounding grass roots. How does it do this?  It can send out roots of its own which in turn invade the roots of neighbouring grasses, hence the occasional reference to ‘vampire’ behaviour. As you can imagine this isn’t great for those unsuspecting grasses which will, as a result, experience a loss in height and vigour. 

With the advantage switched from grasses to yellow rattle, other less dominant wildflowers seize the moment and move in to exploit the emerging opportunity. It’s this ability to help encourage floral diversity which earns yellow rattle the charming nickname of the ‘meadow maker’.  

Greater Yellow-rattle (Rhinanthus angustifolius) growing on the Battleby meadow

That’s a name they would approve of in the environment team at East Dunbartonshire Council.  They have increasingly sown yellow rattle in early autumn on areas they have carefully scarified.  This is followed up with both the seeds of other species and the direct planting of tiny plants of different species.  The yellow ‘meadow magician’ is however is the star ingredient within the floral recipe. A key point in the years thereafter is making sure that mowing is planned for late summer, carefully timed to take place after the yellow rattle and wildflower plants have shed their seeds.

Relaxed mowing regimes and delayed cuts fit neatly with another East Dunbartonshire Council tactic. They’ve identified a reduction in the rotations for grass-cutting as an intervention which they can easily follow, whilst simultaneously gaining biodiversity benefits. Ever adaptable, when the council found they simply couldn’t resource creating any new perennial meadows in 2022 they compensated by sowing annual pictorial flower meadows on roundabouts and along transport corridors whilst protecting ongoing perennial meadow management. This entailed adopting a welcome cut-and-bale strategy for all of their meadow sites. The introduction of soft-track machinery on the wettest areas was another welcome advance, both for the soil structure and aesthetically.

That’s our mechanical cue to return to ‘nature’s lawnmower’, yellow rattle.

Yellow rattle (Rhinanthus minor) seedhead

Yellow rattle is an intriguing name. Why ‘rattle’ you might ask? The answer is remarkably logical, for when it sets seed it makes the sound of a rattle when your brush against the seed pods. Indeed few plants have such a range of fascinating descriptive names. Penny rattle, rattle basket, hay rattle and rattle grass are all ancient local names that capture the essence of the sound those dry seed pods make. In some areas the pods themselves were known as dog’s pennies as they resembled rough coins and formed part of childhood games. 

In Gaelic the common name for yellow rattle is bodach nan claigeann, literally ‘old man of the skulls’. It is also referred to as gleadhran ‘rattling one’ and modhalan buidhe ‘yellow humble one’.

There are many delights with yellow rattle and they aren’t confined to the list of charming names. It holds its nectar quite deep and is thus popular amongst long-tongued bumblebees. Fascinating studies have revealed that yellow rattle is also susceptible to nectar robbing where shorter-tongued bumblebees simply gnaw through the flower to cleverly reach the otherwise unobtainable nectar supply.

What more could you want when it comes to plant gazing? What with ‘vampires’, ‘magicians’ and ‘nectar robbing’ that’s surely more intrigue than most plants offer.  

The best time to see yellow rattle in Scotland is between May and July.