How to Fertilise Your Lawn in Spring, Summer and Autumn

A well-fed lawn is denser, greener and far more resistant to weeds, moss and drought than an unfed one. The grass plants compete more effectively, fill in bare patches faster and recover more quickly from heavy use. Lawn feeding is straightforward once you understand that spring, summer and autumn each call for a different type of fertiliser — and that using the wrong one at the wrong time can do more harm than no feeding at all.

Spring Lawn Feeding

The spring application is the most important of the year. Apply it when the grass begins actively growing again — usually mid-March to April depending on your climate. Spring lawn feeds are high in nitrogen to drive rapid green growth after winter dormancy. Look for a dedicated spring/summer lawn fertiliser with a notably higher first NPK number (such as 12-4-8 or similar). Apply when the soil is moist or rain is forecast — if granules sit on dry grass they can scorch it. Do not apply too early when the ground is still cold; the grass will not be growing and most of the fertiliser will leach away.

Summer Feeding

A midsummer application in June or July helps the lawn maintain good colour and density through the warmest, driest period. Use the same spring/summer product or a balanced lawn feed. Avoid applying in drought conditions or during a heat wave — stressed, dry grass is easily scorched by fertiliser. Water well if no rain follows within 24–48 hours of application. If the summer is particularly wet and the lawn is lush, you may be able to skip this application without seeing any decline.

Autumn Lawn Feeding

This is where many gardeners go wrong. An autumn lawn feed must be low in nitrogen and high in phosphorus and potassium. Applying high nitrogen in autumn drives soft lush growth that cannot harden before winter frosts — the result is disease-prone, frost-damaged turf. A proper autumn lawn feed (typically 4-12-8 or similar) promotes root development, strengthens cell walls, improves disease resistance and prepares the grass for winter. Apply in September or October before the ground gets cold.

How to Apply Lawn Fertiliser

A spreader, either a handheld broadcast type or a wheeled push spreader, gives much more even coverage than hand-spreading. Uneven application leads to patchy growth and possible scorching. Always check the spreader setting on the product label. After application, water in if no rain is expected within 48 hours. Keep children and pets off the lawn until the fertiliser has been watered in and the grass has dried.

What About Moss and Weeds?

Many combined lawn products include moss killer (ferrous sulphate) or selective weedkiller alongside the fertiliser. These combination products are convenient but should be timed appropriately for each active ingredient. A thick, dense, well-fed lawn is itself the best long-term defence against both moss and weeds — gaps in the sward are the entry point for both.