A week or so before the spring equinox Lucie, Yui and Simon from Niwaki Chiltern Street assembled in Southeast London for a working visit to the Horniman Museum & Gardens. At the invitation of Head of Horticulture, Errol Reuben Fernandes, we were there to help his team of permanent staff and volunteers with a time-consuming seasonal task: cutting back the Grasslands Garden.

Errol met us at the entrance to the imposing Arts & Crafts building that houses the museum’s diverse collection of natural wonders, anthropological artefacts and musical instruments. The collection itself is fascinating and the museum’s programme of exhibitions challenges, educates and entertains, but we had loftier ambitions – to learn some new horticultural skills, share some Niwaki tools and enjoy a day in the garden.

With a full day ahead, Errol took us on a whistle-stop tour of the plants and trees encountered en-route to The Bothy (misleadingly named, being in fact a plain suburban 1960s brick building) where the day’s workers had assembled.

Along the way, we got our first taste of the innovative thinking that the Horniman team have devoted to the spaces in their care as Errol revealed that the gravel gardens at the front of the museum, already bursting with rare daffodils, in fact consisted of crushed rubble that had been recycled from demolition work within the grounds.

Taking responsibility for ‘waste’ material may not be the easy way out – it was actually more expensive to crush the material rather than send it to landfill - but it signals an important shift in perspective and opened up new possibilities for the gardeners. In the long run it will save money, since the gravel needs less weeding (manpower), the sorts of plants they can now grow in such a substrate require less water (manpower and resources) and they didn’t need to buy tonnes and tonnes of gravel from elsewhere.

If you haven’t already done so, check out the projects from TERREMOTO landscape architects, LA in Niwaki Field Report 1 which showcase similar hyper-local recycling tactics.

Arriving at The Bothy, we made our introductions, unpacked some fresh Niwaki tools and holsters (to add to the gardeners’ already extensive personal inventories) and pulled on our steel toe cap boots. Or in Lucie’s case, steel-toed Tabi boots – the stealthier choice. Then it was off to the Grasslands Garden.

Perhaps the key feature of the Grasslands Garden is its 15cm layer of gravel that sits atop who knows how many cm of cold damp London clay. The plants themselves are a mixture of largely North American and South African species, few if any of which can tolerate spending a cold south London winter sat in waterlogged soil: the fast draining gravel is required to make whole planting scheme viable.

Errol had already made it clear to us that biodiversity is a key concern in everything they do at the Horniman, ideally undertaken in as naturalistic a way as possible. Case in point: invertebrate habitat piles of carefully stacked waste matter were popping up all over the garden, replacing and extending the capacity of the slightly tired looking anthropomorphised bee shelters installed in the past.

Naturally, the work we would be doing in the Grasslands Garden that day also took into account the need to maintain a healthy eco-system, which in this case meant taking care not to disrupt the invertebrates/pollinators that had laid their eggs in the hollow stems we would be cutting back.

If only there was a way to keep the stems in the same place without them rotting. Resourceful as ever, Errol and the team came up with a highly suitable solution: they would bundle the stems together and tie them to wooden posts standing amongst the plants. That way the hatching insects wake up in almost the right place and the prairie plants get to keep their gravel. Of course, this is a public garden, visited by thousands school children and more, so it was important to make the solution aesthetically pleasing as well as ecologically sound.

We can all agree the dry bundles look great – like shape-shifting corn dollies or strange pagan sculptures – and as Errol pointed out, they attract the attention of visitors, encouraging them to ask more questions and engage.

Straight pine poles employed in the first year have been replaced with chestnut, chosen as much for its resilience as its attractive sinuous curves which further refine the overall sculptural effect of the technique. At this time of the year, the garden doesn’t impress with scale or structure, but these man-made arrangements echo how the garden has looked in those respects and how it will again later in the year.

Undertaking the cutting back was relatively straightforward. To avoid disturbing the root structures we had to take care not to rock the plants around too much. Errols preferred solution was to hug the plant to keep it steady – a very pleasant instruction giving us a chance to appreciate the textures and smells as well as the look of the dried stems.

Choice of tool was also important. We used a mix of Herbaceous Sickles, Mini Shears and GR Pro Secateurs, with the occasional bit of Hori Hori action to clear any weeds we encountered. We were told to aim for good clean, low cuts, as close to the base of the plants as possible without damaging any fresh growth that we discovered along the way and tidying up any loose material that didn’t make it to the bundle.

It was also very important to look where we were walking as these beds are tightly planted with all sorts of well hidden plants. What looked like a heap of dead straw was in fact cover for the early shoots of one of the first flowers to emerge in the garden – Pulsatilla vulgaris (pipped to the post by some spectacular Bulbinella).

It was slow satisfying work. We tried to work on one species at a time to create relatively uniform bundles that were then laid out on a large tarp ready for assembling and erecting. It was at least a two man job to get them tied tightly with coir twine to the chestnut posts where they would remain until mid-June. Competition for the neatest, most attractive bundle was high and the whole team beamed with pride once the job was completed. They do look great don’t they?

Thanks to Errol and all the team at the Horniman – we can’t wait to return and meet the insects we’ve helped usher into the garden this summer.