Northern exposure

Innovative 21st-century composting and mulching techniques combined with a 19th-century shelterbelt ensure that these famous gardens continue to thrive, writes Caroline Donald

- Caroline Donald

IT is a privilege indeed for COUNTRY LIFE to be shown the large composting area at the National Trust for Scotland’s (NTS) 54-acre garden at Inverewe on Loch Ewe in Wester Ross. ‘I don’t bring many people up here,’ says Kevin Ball, who has been head gardener since 2006.

Composting has always been important in a garden conjured from bare rock and Mr Ball and his team pride themselves on producing large volumes of high-quality material within six months. It is here that woody and herbaceous waste, seaweed gathered from the shoreline and all the bamboo cutlery and paper cups and plates from the café end up. The materials are layered like a lasagne in long windrows and monitored by a digital probe to alert the gardeners when the heap gets close to 60°C, so it can be turned (five times), then moved to another area to decompose further before being returned to the garden. ‘It’s a very professional system,’ says Mr Ball. ‘It kills off all the weed seeds and the nasty diseases and pathogens.’

That's not all there is to admire backstage: next, the Exeter retort, a large metal drum on wheels that can be moved around the estate or lent to other NTS gardens. It is where the team makes biochar, a premium-quality charcoal created without oxygen to produce pure carbon in a process called pyrolysis. It is then crumbled and added to the compost as a supersonic soil improver to neutralise acidity, improve water and nutrient retention, aerate and offer habitats for microbes.