How we make our own soil

At the Diggers Preservation Garden and trial grounds we produce quite a bit of green waste, but none of it is ever wasted. We recycle it.

Diggers gardens are certified-organic gardens, so it is vital to know the origins of the soil on each of our sites. Since the Diggers Preservation Garden inception in 2013-14, Diggers has recycled our waste into our soils.

The Diggers Preservation Garden is continually improved and replenished through the generation of our own ‘black gold’ soil, more commonly known as compost.

How long does the composting process take?

The composting process varies depending on the weather, and the composition of your compost heap.  Three-to-six months is a minimum, with six-to-twelve months more common.  Aeration of the compost heap is important to keep the process working aerobically, as well as the addition of water in dry weather.

Using a garden fork, we regularly turn soil to balance moisture and circulate air throughout the compost heap.  When the compost bin or heap is full, we start a new heap for new waste and future compost.

What are the essential ingredients for great compost?

Composed of a combination of pure, raw materials, Diggers ‘black gold’ (above) contains:

• Raw materials from our 20 acre garden and nursery (including fallen/broken limbs of endemic trees and shrubs), which are shredded and broken down further by detrivores;
• Green waste from our gardens;
• Nitrogenous weeds (including Sonchus sp.);
• Old spent flower blooms and other vegetative material collected at our preservation garden including prunings, weeding, etc;
• Plastic-free waste from our production nursery which includes perlite, vermiculite, spent potting mixes (which are soil-less) and green waste (plants that don’t make the cut);
• Cut or slashed pasture from the remaining land awaiting trial plantings;
• Locally supplied and organic certified chicken manure to improve nutrient content of the compost and to improve the heating process within the compost heap.

While Diggers produces a lot of green waste suited to composting, it is equivalent to that produced in a home garden, with the quantity of ‘black gold’ required at home relative to the green waste produced.

What to include in your compost

• Organic manures including chicken, cow, goat and sheep;
• Wood by-products such as fallen limbs and branches (chipped or shredded);
• Leaves and leaf matter;
• Slashed and cut grass;
• Pea straws, lucernes, sugar cane, etc.
• Graded, screened sandy loams or sand to improve drainage;
• Garden waste (all forms);
• Food waste (kitchen scraps – not meat, onion or citrus);
• Beneficial fungi such as Mycogold.  Encourage microbial activity by adding biochar to the compost heap.

What not to include in your compost

• Horse manure (high-weed seed manure)
• Blackberries and other noxious weeds
• Plastic
• Non-biodegradables
• Meat and meat products

The Diggers Preservation Garden

Our commitment to sustainability is a constant narrative that inspires us to recycle, re-use and return our horticultural waste back into the soil as part of the web of life. 

This creates the sustainable soil/growing media that is the foundation of our trial and production gardens and is even available to our heritage gardens of Heronswood and St Erth.

This holistic approach of The Diggers Foundation is crucial to the mission, and our environmental message that we share with our members.  This approach to waste management requires minimal input and has few miles compared to imported resources.  We take responsibility for the soil and thus the plants produced in them.

There is nothing more rewarding for a gardener than to feel the texture of the soil and smell the sweetness it exudes.  Revelling in the complexities and wonderment that has been created is an immensely fulfilling and proud moment.

Marion Cran, the first female gardening broadcaster and a highly successful writer in Britain wrote, “If I wanted to have a happy garden, I must ally myself with my soil; study and help it to the utmost, untiringly.  Always the soil must come first.”

“Essentially, all life depends upon the soil … there can be no life without soil and no soil without life, they have evolved together.”  – Charles Kellogg, author of Our Garden Soils, Macmillan, 1952