Feeding your lawn with the right fertiliser at the right time of year makes a noticeable difference to its colour, strength and resilience. Fertilising supports root growth, improves recovery from wear and helps the grass compete with weeds and moss. But timing is everything. Applying fertiliser when the grass isn’t actively growing wastes product and can even harm your lawn. With the right seasonal approach, you can keep your turf thick, green and healthy all year round.
Start in Spring Once Growth Begins
The first fertiliser application of the year should take place in early to mid-spring, typically between March and April once the grass has started growing and the soil has warmed up. Choose a high-nitrogen spring lawn fertiliser to encourage strong blade growth and rich green colour. It’s best to fertilise after the first mow of the season when the grass is actively taking in nutrients.
Avoid feeding too early in the year, especially if the soil is still cold or waterlogged. Fertiliser applied under these conditions is less effective and more likely to run off or leach through the soil.
Follow Up in Early Summer
A second round of fertiliser in late spring or early summer, around May to June, helps maintain growth and support the lawn during peak use. By this time, the grass is growing at full pace and benefits from a balanced fertiliser that continues to support foliage while beginning to strengthen roots.
If you expect dry summer weather, switch to a slow-release formulation to prevent soft growth that will struggle in drought. Always water in fertiliser if rain isn’t forecast within 24 hours to avoid scorching and ensure the nutrients are absorbed.
Autumn Fertilising for Root Strength
The most important feed for long-term lawn health happens in early autumn, typically between late September and early November. At this time of year, growth above ground slows down, but the roots are still active. An autumn lawn fertiliser is low in nitrogen and higher in potassium and phosphorus, helping roots grow deeper and making the grass more resilient to winter stress.
Feeding at this stage improves colour retention through colder months and gives the lawn a head start in spring. Avoid using spring or summer fertilisers in autumn, as they encourage top growth that’s vulnerable to frost and disease.
Don’t Fertilise in Winter
In the UK, winter fertilising is not recommended. Grass goes dormant once soil temperatures fall below 5 to 6°C and cannot absorb nutrients effectively. Applying fertiliser at this time can lead to nutrient run-off, wasted product and potential damage to the soil or nearby waterways. Instead, focus on lawn protection during winter and resume fertilising when growth returns in spring.
Special Considerations for New Lawns
Newly seeded or recently laid lawns should be treated with care. Avoid fertilising until the grass has been mown two or three times. This confirms the roots are established and strong enough to handle additional nutrients. When you do fertilise, use a starter fertiliser specifically designed for young grass, which promotes steady development without overloading the blades.
Soil Testing Can Sharpen Your Timing
Most homeowners fertilise based on the season alone, but for more precise results, a basic soil test can help determine exactly when and what to apply. These tests reveal nutrient imbalancesespecially low nitrogen or phosphorusthat could delay growth even if the timing seems right. If your lawn isn’t responding well to fertiliser despite good timing, the soil may not be holding or releasing nutrients effectively.
The Type of Grass Affects Feeding Schedules
Cool-season grasses like ryegrass and fescue dominate most UK lawns. These grasses grow most actively in spring and autumn, which is why feeding during these seasons is more effective. Unlike warm-season grasses, they don’t benefit from heavy summer feeding, especially if the weather is hot or dry. Understanding your grass type ensures you don’t feed at the wrong time for its growth cycle.
Mow Before, Not After, You Feed
Fertiliser works best when applied to recently mown grass, not freshly cut. Mowing just before feeding ensures more even contact with the soil and reduces the risk of fertiliser sitting on top of long blades, where it may cause scorching or waste. Always leave a few days after feeding before mowing again to allow absorption and avoid lifting granules off the surface.
Wet vs Dry Conditions Matter
Fertiliser should always be applied when the grass is dry but the soil is slightly moist. This reduces the chance of leaf burn and improves nutrient uptake. Applying fertiliser just before light rain or watering it in manually is ideal. Never fertilise frozen, frosted or waterlogged lawns, nutrients won’t be absorbed and could run off into drains or flowerbeds.
Feeding Frequency Depends on the Product
Some homeowners overfeed simply because they don’t realise how long different products last. Slow-release fertilisers can last 8 to 12 weeks, while fast-acting feeds may only last 3 to 4 weeks. Stick to the product’s guidance, more is not better. Over-fertilising leads to soft growth, greater disease risk and potential environmental harm from nutrient leaching.
Keep Feeding Away from Hard Surfaces
When spreading fertiliser near paths, patios or driveways, avoid overspill. Fertiliser left on hard surfaces can wash into drains, causing water pollution and wasting nutrients. Sweep up stray granules immediately after application, and apply with a spreader if possible for better control
Final Word
Fertilising your lawn at the right time keeps your grass healthy, strong and better equipped to deal with wear, weeds, drought and disease. Spring builds growth, summer maintains strength, and autumn prepares the lawn for winter. Match your fertiliser to the season and your lawn’s condition, and you’ll enjoy vibrant, thick turf across every part of the year.
