Mind Your Margins

The margins of your field provide space for nature on your farm. They can be your valuable contribution to biodiversity provided they are not fertilised or sprayed. And biodiversity is in crisis so every little helps. Biodiversity includes flora, fauna and the habitats in which they exist. Not all flora and fauna are good – our native flora and fauna are best as they have been here for ten thousand years since the last ice age and are in tune with each other. The life cycle of our native bees, butterflies and moths is in harmony with the plants and trees on which they depend. Invasive Alien Species, ornamental species and introduced species are not good for biodiversity on farmland.

Field margins are linear habitats. This means they are corridors of movement and networks for nature in the countryside. Birds, bats, bees and butterflies fly along linear habitats such as hedges watercourses and field margins to find prey. Barn owls find shrews in the grassy margins. Hedge banks are a specific habitat with a different suite of flora and associated fauna depending on their aspect. Primroses and lesser celandines appear early on south facing banks, while ferns thrive on north facing banks.

Be aware of the plants in your field margins – plant identification apps can help to identify and investigate further. Our native wildflowers grow in low nutrient soil and cannot survive where fertiliser, slurry or lime is added. As you do your grass walk this week – look out for the following plants in your field margins – all part of our native Irish biodiversity.

• Look out for dandelions, the most important flower for our wild bees according to the Biodiversity Data Centre, who receive records of bee sightings, including information about what the bee was feeding on. In 2022 from 1,482 bee records submitted, the dandelion was by far the most popular. Wild bees are in trouble mainly because of hunger. They need plants that provide the best source of pollen and nectar. The dandelion flower head is a composite of hundreds of individual florets and provides an early supply for bumblebees, solitary bees, honeybees, hoverflies, butterflies and other insects emerging from nests or from dormancy at this time of year.

• Look out for primroses on south facing banks. Delicate pale yellow petals deep yellow in the centre converge into a long tube. This contains nectar at the base, which is only accessible to long tongued species of bumblebees, bee-flies and butterflies. Bee-flies have two wings but otherwise look like bees. A butterfly whose lifecycle is in tune with primroses is the brimstone butterfly. The male has luminous yellow wings while the female is pale green. They emerge from hibernation now having overwintered as adults and feed on primroses on sunny days. Primroses, nó sabhaircín, are widely recognised and welcomed as one of the signs of spring.

• Look out for occasional bright shiny yellow flowers of lesser celandine, already making an appearance on roadside margins, which have been left to grow wild naturally. At first glance it can be mistaken for buttercup but has 8-9 petals compared to five. The heart shaped leaves on hollow stems grow early to avoid being shaded out by grasses and other vegetation. Expected lower temperatures may delay the very obvious display of golden starflowers, but they will come in early spring. The leaves and flowers will then vanish, with the plant remaining below ground for most of the year in fig-like tubers.

• Look out for tutsan with its last remaining black berry-like capsules, which have transformed from their bright red colour last autumn. This low growing woody species can be up to a metre high with woody stems at the base. It is a semi-evergreen with broad oval hairless leaves and tiny translucent dots. Found in deciduous woodlands and hedges in slightly damp areas, only a few individual plants grow in an area – never dominating. Often found with other less common species – it indicates a valuable hedge margin, which has not been sprayed or cultivated. Tutsan is the native member of St. John’s-wort family.