In one of the last fields of wheat to be cut, a large white butterfly skims the top of the parched crop. The two black dots on each flapping forewing bring a polka-dot touch to the monochrome field. Through the heat, its flutter brings a welcome motion. Otherwise, it is still, quiet, only the sound of fallen stems crunching underfoot. Where the butterfly lands, a cluster of oxeye daisies gleams, sheltered from the glare by the wheat.
In the next field, the hill rises, newly shorn. The sky blares blue above low gold stalks, no trace of cloud, no breath of wind. In the stripped fields, there are tiny patches of white, where wild radish (Raphanus raphanistrum) has survived. It has many other common names, including wild charlock, runch, wild turnip and wild kale, as well as several variations of radish: jointed, jointed wild, fodder, and the more generic moniker, white weed.
Raphanus stems from the Greek for appearing quickly, in line with its rapid germination. It is able to flower several times a year, has a deep taproot, and its seeds can lie dormant in the soil for years. This resilience, enhanced by its flowering below the cutting height and ability to shed seeds just before harvest, lessens the impact of this seasonal disturbance.
As a cover crop, this white “weed”, as some see it, can improve soil health. Its deep root system breaks up compacted soil, and improves water penetration and aeration. All parts of the plant are edible, giving a peppery taste, and it is also a food source for many insects and birds, and a host for the large white butterfly’s larvae. Another of the butterfly’s common names, cabbage white, and its Latin name, Pieris brassicae, also reflect the longstanding link between insect and plant, since the radish is a member of the Brassicaceae (mustard or cabbage) family.
When another white butterfly floats over the sandy stubble and flits around the radish’s petals, it is like a ripple of water in an oasis. A small movement through the heat; a tiny cloud, a breath of wing.
• Under the Changing Skies: The Best of the Guardian’s Country Diary, 2018-2024 is published by Guardian Faber; order at guardianbookshop.com and get a 15% discount
