Organic fertilisers are made from organic materials rather than from soluble chemical fertilisers.

The difference between organic fertilisers and chemical fertilisers is that soluble chemical fertilisers contain mineral salts. While these are immediately able to be used by plant roots, they do not aid the soil or soil inhabitants and indeed can be an eventual problem due to acidifying the soil and repelling earthworms and other useful soil dwellers. The organic matter decreases in soils treated constantly with chemical fertilisers over time, necessitating even more chemical fertilisers as the soil becomes more depleted of nutrients.

Organic fertilisers add to the soil as well as feeding the plants. They act as both plant feeder and soil conditioner. This is the principal aim of the organic gardener or farmer, providing a holistic outcome that keeps the living soil healthy and the plant life nourished.

Use of organic fertilisers should be done with thorough research into the type being used to ensure that it is appropriate for soil type, plants being grown and the amounts/timing/preparation needed.

Organic fertilisers include:

• Compost
• Composted manure
• Seaweed - powdered, shredded, liquid form
• Kelp meal
• Peat
• Moss
• Mica
• Bone meal, blood meal, fish emulsion (not suitable for vegetarian/vegan gardeners)
• Epsom salts
• Basalt
• Dolomitic limestone
• Worm castings
• Soybean or other suitable crop meal
• Wood ashes (but care must be taken with how much is used)