Botanical garden, Isle of Man

Since 2018, we have been engaged to design two large sites, based on New Zealand’s distinctive landscapes and flora, at Mallards Estate – a botanical garden in development on Isle of Man. These New Zealand gardens are closer to the scale of parkland, and are the first of a series of gardens based on interesting temperate biomes to be developed at Mallards.

Beyond designing botanical collections as cohesive and compelling landscapes (in which geology and geomorphology are also considered), one of the primary challenges associated with a project of this nature is the practical matter of how plants from our latitudes translate to the substantially different latitudes of the United Kingdom.

In the Southern Hemisphere, the opposing latitude to Isle of Man sits to the south of the Subantarctic Islands, whilst even London’s equivalent latitude flies hundreds of kilometres below the southern tip of NZ’s main islands.

An understanding of the role of daylight hours for plant growth is fundamental to horticulture. Whilst the difference in daylight hours between Isle of Man and New Zealand at the winter solstice (between 1.5 and 2.5 hours, depending on which point in NZ one refers to) certainly doesn’t preclude the cultivation of our plants in this climate, it is a significant factor in how one approaches a design process.

For example, the cultivation of species from Northland (whose latitude aligns more closely with southern Greece) makes little sense on this project – especially when one considers the vast diversity of plant life along the length and breadth of our islands. Accordingly, the core of our design is based on regions of New Zealand whose latitude, temperature range, and maritime influence are better suited to northern parts of the UK.

As part of Philip’s initial visit to Mallards, he visited Royal Botanic Garden Edinburgh to observe a significant collection of New Zealand species grown at a comparable latitude. We also conducted exhaustive research into the range of NZ plants that are grown by nurseries and botanic gardens in the UK and Ireland – to add to the experience that Philip garnered from working on Chelsea Flower Show in 2006, and the lessons that he learnt from James Fraser (who has developed a deep knowledge of how our flora behaves in the United Kingdom).

Site analysis included looking into local conditions and the soil environment at Mallards (and Isle of Man in general), local geology (in which granite is one of the primary stone types), management practices at Mallards, and the variables that the two sites presented. In line with the differing character of the respective sites, one area is designed primarily as an ‘open’ environment (with shrubland, tussock and woodland edge), whilst the other site will comprise a sequence of forested environments.

On the basis that the Mallards team will be responsible for practical aspects of installing the project, it was wise (and indeed necessary) that they gained firsthand experience of New Zealand. Unless one has seen how environments morph into differing geological substrates, or understands the varied geomorphology of a country or region, everything is simply theoretical.

With this in mind, two key members at Mallards (including the project lead, Andrew) came to New Zealand to visit landscapes that were directly relevant to the project. During this trip, we showed Andrew and Ollie around a number of interesting landscapes – including ultramafic vegetation and montane plant communities in northern Southland, beech forest, and coastal woodland on the margins of Cook Strait.

Development of the botanical collection has commenced according to a rigorous process, with our continued involvement in seed procurement (including identifying preferred sources for accessions). Execution of the designs will take place over several years, during which procurement will continue in line with seasonal variation in the seeding of our native plants (which is not always predictable).

New Zealand’s geological diversity is recognised within the overall design, with species from limestone, ultramafic (or serpentine) and dolomite habitats specified. The diversity of kōwhai (members of the genus Sophora) is a particularly good case study of adaptive radiation that is driven in part by geological variation.

One of our primary design intentions is to establish a series of environments that feel seamless and communicate some of the character of our landscapes. Many botanical gardens focus on the plant as individual, whilst Mallards has a strong focus on diversity and the way in which plants interact.

The relationship between plant communities and environmental conditions is of central importance to the design – with topography, edaphic conditions, the varying paths of water and response to wind just some of the factors at play in the composition of the various zones through which one will pass.

Landscape is defined by the confluence of landform, plant and animal life, geology and weather, and fascination with the diversity driven by these natural protagonists sits at the heart of this project.