Using organic fertilisers not only feeds your lawn, but also supports soil health, biodiversity and resilience against pests and diseases
Spring has well and truly sprung, and experts are encouraging gardeners to apply natural fertilisers to promote lush, healthy growth and prepare their lawns for the brutal months ahead.
Timing is important, so it’s best to apply fertilisers in early to mid-spring, when grass is actively growing but before the summer heat arrives.
Growers are increasingly turning to sustainable practices. Among the most highly recommended organic fertilisers are the following four, each of which offers unique benefits and plays a vital role in building a healthy and productive yard.
Compost
Compost is often considered the gold standard of natural fertilisers. Made from decomposed plant material, kitchen scraps and sometimes animal manure, it is rich in organic matter and contains a wide range of nutrients including calcium, magnesium and sulphur, as well as traces of elements like iron, copper, manganese, boron, molybdenum, chlorine, zinc and nickel.
Unlike synthetic fertilisers, compost not only feeds plants but also improves soil structure, water retention and aeration. It encourages the proliferation of beneficial soil microorganisms and earthworms, which further break down organic material and make nutrients more available to plants.
For lawns, a thin layer of compost can be spread in spring or autumn to boost grass growth and soil vitality. In gardens, compost is ideal for vegetable beds and flower borders, as well as around trees and shrubs. Its slow release of nutrients ensures steady, healthy plant growth without the risk of burning roots or leaching nutrients.
Chicken (and other animal) manure
Animal manures, particularly chicken manure, are excellent sources of nitrogen, a nutrient essential for leafy growth. Manures also provide phosphorus, potassium and a host of micronutrients. However, fresh animal manure can be too strong and may burn plants, so it’s best used after composting or aging for several months.
Chicken manure is especially potent, making it ideal for lawns, fruit trees and vegetable gardens that require a nitrogen boost.
Cow, sheep and horse manures are also beneficial, though generally less concentrated than chicken manure. Manures improve soil fertility and structure, encourage microbial activity and help retain moisture.
Rock phosphate
Rock phosphate is a naturally occurring mineral that provides a slow-release source of phosphorus — a key nutrient for root development, flowering and fruiting.
Unlike synthetic phosphorus fertilisers, rock phosphate is less soluble, meaning it releases nutrients gradually over time, reducing the risk of runoff and environmental harm.
Rock phosphate is particularly valuable in soils with low phosphorus levels or for crops with high phosphorus demands, such as root vegetables and flowering plants. It is most effective when worked into the soil before planting, or when used as a top dressing for plants that are already established.
Plant and seaweed-based fertilisers
Plant-based fertilisers — including those made from alfalfa, comfrey or nettles — provide a balanced range of nutrients and are typically gentle on plants.
Seaweed-based fertilisers, such as liquid seaweed or kelp extracts, are especially prized for their trace minerals, growth hormones and ability to stimulate soil life.
Liquid seaweed can be used as a foliar spray or soil drench, providing a quick nutrient boost during periods of high demand, such as flowering or rapid growth. These fertilisers enhance plant resilience to stress, improve root health, and support overall soil fertility.
