(adapted from an article that appeared in Natur Cymru)

The National Botanic Garden of Wales (NBGW) is far more than its formal gardens and great glasshouse, there is also a wonderful organic farm spread over 20 fields and covering 400 acres. This is managed not only as a working farm but as one that actively encourages the spread of native wild plants.

When the NBGW took possession of the land in the 1990s, it was clear that much of the farmland had escaped the intensive agricultural treatments that had affected so much of the British countryside. The Gardens had therefore inherited meadows and pastures that contain plants that are now no longer commonly found in the countryside. However, some deterioration had occurred – a gradual spread of rushes and coarse grasses had occurred and traditional hay making had been replaced by silage production.

The Gardens, wishing to maintain and improve conditions on site to allow the native species to thrive, had to decide how to best carry this out. It was decided that no chemical fertilizers and sprays would be used and that organic farming principles would be followed. Herbicide use was stopped as it could not be assured that inadvertent damage might not occur to important life in the soil.

Surveys were undertaken of the land to gain a better understanding of the ecological value of the habitat and to help prioritize where and what type management was needed – cutting or grazing and grazing with what type of animal.

In the years that the NBGW have been managing the land lessons have been learnt about the various management techniques used to improve the biodiversity on site and techniques refined.

Hay cutting and removing the cut grass reduced the fertility of the soil, which allowed more wildflowers to establish. In a slight change in management not all the fields were cut at once with small grassy refuges being left – cutting all the field suddenly removes the shelter and food source for insects, small mammals and birds. These uncut areas were rotated every year.

A grazing regime was also developed and now is applied in a pattern of spring cattle grazing to keep the larger grasses in check and autumn grazing to poach the ground and provide areas for seed establishment. Cattle were chosen over horses and sheep, the latter being very fussy grazers, whilst the Garden’s Welsh black cattle are not so selective and are good at removing coarse vegetation. Also, if the fields are not overstocked cattle can produce an interesting mosaic of grass heights, providing useful refuges for invertebrates.

In wet areas cattle will trample and poach – they can cause damage to sensitive plants and allow invasive weeds to flourish but limited trampling can allow seeds  deeper into the soil to germinate and provide gaps for new flowers to establish. Cattle are also excellent for trampling down the invasive soft rush and the larger willow and alder scrub.

Over the years as a result of this management, finer grasses and colourful flowers such as knapweed, self heal, betony, devil’s bit scabious, yellow rattle, stitchworts and greater butterfly orchid have become established.

Sheep are also a management tool on selected well-drained pastures. Tight grazing allows for the establishment of a variety of waxcap fungi, with their vivid colours of yellow, pink, orange, white, green and red. A 2007 CCW-funded survey found at least 18 species of Hydrocybe waxcap species just on one hillside alongside other important waxcap species. The presence of these fungi is a strong indicator of long-term non-intensive farming practices. Sheep grazing is essential to their continued presence as they do not like competition at their fruiting time from long grasses.

Management needs to be active – if left with no management wildflower meadows quickly deteriorate and become invaded with coarse weeds and scrub over.

Tim Bevan at the Garden who manages the farm hopes to increase cattle grazing on some of the more agriculturally improved fields to try and create the ‘mosaic’ habitat with more clumpy grassland with varying heights of grass cover.

Monitoring will be undertaken to make sure the current management is correct and that the right conditions are being provided for the variety of plants to survive. Maps of the all the grassland will be created showing the types of plant communities present – regular surveys will show any changes to the plant communities as a result of the conservation management being undertaken.