RHS SylvaGrow Farmyard SylvaGrow Farmyard is made from anaerobic digestate which is a by-product of renewable energy production. An excellent soil improver that provides gardeners with a 100% peat-free, rich source of organic matter for all soils. SylvaGrow adds nutrients to the soil, which improves fertility and yields. Enhancing soil structure and workability and increasing water-holding capacity. SylvaGrow is exclusively obtained from a partnership with the Duchy of Cornwall and local farmers near Dorchester, Dorset. Containing up to 20% certified green compost for a further organic matter boost.