Loam is the most important ingredient as it provides a natural reservoir of plant foods, trace elements and contains some organic matter which releases nitrogen slowly to the plant. The loam in J. Arthur Bower’s John Innes is screened and sterilised to avoid any soil-borne diseases and insects
The sphagnum moss peat in John Innes compost improves both the aeration and water-retaining capicity, which enables the compost to make maximum use of the nutrients and trace elements in fertilisers.
Lime-free grit sand is included to allow excess water to drain from the compost and so prevent waterlogging. It also adds weight and provides stability for pot grown plants.
Ground horticultural-grade limestone is added to give the compost the pH most plants prefer. For lime-hating plants choose ERICACEOUS compost instead.
The compound fertiliser in John Innes provides the wide spectrum of plant nutrients needed for healthy growth. These include nitrogen for leafy growth, phosphates for root development, potash for flowering and fruiting and trace elements for colour and flavour.