Healthy homemade fertiliser begins with healthy compost. Compost is not a quick chemical feed. It is a stable soil amendment made as microorganisms break down food scraps and garden material in the presence of oxygen. Finished compost can improve soil structure, help soil retain water and slowly return nutrients to the garden.
Build a balanced pile with roughly two to three buckets of dry brown material for each bucket of fresh green material. Browns include dry leaves, shredded plain cardboard and small twigs. Greens include fruit and vegetable scraps, coffee grounds and fresh grass clippings. Chop large pieces so they break down evenly. Keep the pile about as damp as a wrung-out sponge, and turn it regularly so oxygen reaches the centre. A healthy pile should smell earthy rather than sour.
Avoid meat, fish, dairy products, fats, pet waste, diseased plants, glossy packaging and weeds carrying mature seeds. These materials can attract pests, introduce unwanted organisms or make a small home system difficult to manage. If the pile smells unpleasant, add dry leaves or cardboard and turn it. If nothing is happening, add a little water and more green material.
Compost is ready when it is dark, crumbly and no longer resembles the original scraps. Mix a modest amount through garden soil or spread it as a surface layer, keeping it away from plant stems. More is not always better. Healthy plants also need suitable light, water, drainage and the right soil pH. Compost supports that whole system rather than replacing it.
Reference: United States Environmental Protection Agency: Composting at home.
