The structure of Pro-Grow Potting & Container Compost encourages healthy root growth and retains soil moisture. It will improve soil fertility, break down heavy clay soils and add humus to sandy soils if used as a soil improver. Contains a slow release fertiliser to give plants a boost after planting. This versatile multi-purpose compost is ideal for sowing seeds, rooting cuttings, transplanting seedlings, potting up containers & baskets and planting out in the garden.