What have cows got do with fairy rings?

'May Day' stems from the fire festival of Beltane that celebrates the beginning of summer and the fertility of the coming year. Beltane is a Celtic word which means 'fires of Bel' (Bel was a Celtic deity). In springtime, at the beginning of the farming calendar, everybody would be hoping for a fruitful year for their families and fields. Most of the customs centre around flowers, greenery and at one time the 'hobby-horse'. So dancing round the maypole, dressing up as a fool with a bladder-on-a-stick and Morris dancing can all be blamed on Bel can it?

It is said that a maiden can improve her looks by bathing her face in dew collected on a May morning. However, it’s not that simple. If the dew is collected from inside a fairy ring, then her appearance is turned into that of an old crone, complete with spots and blemishes. O-kaaaaaaay! I hear what you’re saying but come on! Is it really likely? Dew may be extremely pure water but if it had those kinds of properties don’t you think Estee Lauder might be onto it by now?

So what are fairy rings? Usually, a fairy ring is visible as a noticeable circle appearing in grass. Some rings look like a circle of grass that is darker at the edges than it is in the centre. Others look like a ring of poor-growth or bare earth. Fairy rings were thought to be the result of fairies dancing in a circle. No, don’t laugh! Another explanation held cow’s rear ends to blame! Cattle feeding on bales of hay invariably form a circle around their food, and what happens around the back? Yes, instant fertiliser, which means a circle of greener grass. Nice try, cow fans, but in actual fact fairy rings are all down to fungi.

The fairy ring was identified as a fungal growth pattern in 1792 by William Withering. It was due to a species called Marasmius oreades, whose modern common name is the fairy ring mushroom. This is one of 60 or so different species which produce fairy rings.

All fairy rings are produced in the same manner. Initially a spore (the fungal equivalent of a seed) lands on some suitable ground. It starts to grow underground, pushing out mycelium (fungal threads – the actual body of the fungus itself) in all directions. Eventually the central part dies off, leaving a disc of mycelium growing at the outer edge. Fungi release digestive chemicals (enzymes) into the ground to break down their food, which they then suck up. Unfortunately, they are sloppy eaters and not all of this digested food is taken up. The leftover nutrients are used by the surrounding plants. As a result of this, the grass grows more luxuriantly at the leading edge where the extra food supply is present. Meanwhile the death of the mycelium at the trailing (inner) edge returns nutrients to the soil, also stimulating a growth of grass.

Eventually fruit bodies (usually in the form of mushrooms) are produced to release spores and start the cycle again. Sometimes, several years may go by before mushrooms are actually seen at a fairy ring. Fairy rings may not be complete circles, as parts of the circle of mycelium become damaged and die off, leaving a crescent shape. So now you know! Fairies indeed…