Earthlite™: The Smart Planting Medium for a Changing Climate

In an era of shifting climates, increasing urbanisation, and pressure to reduce waste, the future of garden and landscape design lies not only in the choice of plants but also in the soil beneath our feet. At Bestall & Co, we’ve spent the last four years researching, refining, and trialling a new sustainable growing medium that addresses the challenges of modern planting: Earthlite™.

Rethinking the Foundations of Planting

Traditionally, planting mediums have been overlooked in favour of visual elements like plant choice and layout. However, as any experienced gardener or designer knows, the health of a landscape starts from below the surface. Earthlite™ was born from our desire to develop an ecologically responsible substrate for planting schemes that would perform across a wide range of conditions, particularly those brought about by our changing climate.

Much of our research began with a simple yet urgent question: What if some of the waste we are removing from site can be reused as a growing medium and could actively contribute to climate resilience, biodiversity, and sustainability all at once? The result was Earthlite™, a blend that harmonises science, nature and horticultural experience.

Why Earthlite™?

At its core, Earthlite™ is an aggregate blend created to mimic the physical and chemical properties of some natural soils while improving upon them with recycled materials, preventing their disposal from site. It is composed primarily of crushed concrete, stone and brick rubble, but can also include block paving, clay roof tiles, sandstone, limestone, pressed slabs and slate – often by-products of urban demolition combined with carefully graded loam and organic matter. This blend offers excellent drainage, structural stability, and a surprising richness in essential minerals like calcium, magnesium, and phosphorus.

But what truly sets Earthlite™ apart is how it reflects the principles of regional diversity and climate-conscious planting.

Drawing from the Science

As outlined in the wider horticultural industry literature, recycled aggregates such as crushed concrete and brick are increasingly being recognised for their unique properties. Crushed concrete, for example, contains high levels of calcium carbonate, a by-product of the cement used in its original form. As concrete ages and weathers, it absorbs carbon dioxide (CO₂) from the atmosphere in a process known as carbonation, eventually forming more calcium carbonate. This reaction not only makes crushed concrete an ideal medium for lime-loving plants but also introduces a secondary carbon sink—a small but meaningful way to offset greenhouse emissions from its initial manufacture.

Brick rubble adds an entirely different dimension. Rich in phosphorus, potassium, and magnesium, brick-based materials contribute to nutrient diversity. Their clay-like origin also enhances moisture retention, while their fragmented structure maintains aeration—striking a balance between drainage and water-holding capacity.

Learning from Experience

Over four years of field trials in real gardens, Bestall & Co have tested Earthlite™ in a wide variety of settings, from sunny open slopes to partially shaded urban courtyards. We’ve observed that, much like naturally formed soils, this medium undergoes a slow evolution: its pH, moisture balance, and microbial activity shift as it is colonised by plant roots, fungi, and invertebrates.

Some unexpected benefits emerged too. The high mineral content in Earthlite™ enhances sunlight reflection off the soil surface, a boon for heat-loving plants that need a little extra energy to thrive in the UK’s cooler summers. In time, Earthlite™ supports the natural accumulation of organic matter through leaf drop and decay, forming a living, breathing medium that mimics the successional processes found in wild habitats.

A Medium for a New Generation of Planting

What makes Earthlite™ so appropriate for today’s planting is its reclaimed ‘on-site’ advantages.  Rather than importing planting medium, the Earthlite™ is designed to be created from what is available on site – meaning you can control exactly what goes in and exclude anything ‘un natural’ like tarmac, asbestos, plastic and plaster as well as wood and glass that can sometimes be found in imported recycled products.

In urban settings, where planting beds often sit atop concrete slabs or rubble, Earthlite™ provides a lightweight, free-draining base that also retains enough moisture to support a wide palette of perennials and grasses. In exposed rural settings, it mimics the resilient, mineral-rich soils of natural grasslands.

As we’ve developed this material, we’ve designed Earthlite™ planting schemes around matrix planting principles, diverse, layered communities with a backbone of grasses, dotted with flowering perennials and structural accents. These schemes support greater biodiversity, require less maintenance, and withstand drought, heavy rainfall, and other environmental stressors.

Right Medium, Right Place

Choosing the correct medium isn’t about finding a one-size-fits-all solution, it’s about responding intelligently to the site. Earthlite™ is not a generic product; it’s a tailored approach to soil creation. Its formulation can be adjusted for specific projects, whether the goal is better drainage, higher nutrient availability, or a leaner, more competitive environment that favours slow-growing species.

Understanding how recycled aggregates function as soil, how they absorb moisture, release nutrients, and support biodiversity is key. With Earthlite™, Bestall & Co is not just using waste; we’re rethinking it, transforming it into a horticultural asset.

The Future of Sustainable Soil

At Bestall & Co, we believe that Earthlite™ represents the next step in landscape sustainability. As climate change continues to challenge traditional planting techniques, the need for intelligent, resilient substrates has never been greater.

Earthlite™ is more than a medium, it’s a movement towards regenerative landscaping, where the materials we use echo the environments we hope to protect. It empowers designers to make informed, climate-adaptive choices, and gives plants the foundation they need to thrive, not just now, but in the long term.