Why Is My Lawn Yellow? Causes & How to Fix It
A yellow lawn is usually a cry for help. Learn the 6 most common causes of yellowing grass in the UK and exactly how to diagnose and fix each one.
Diagnose the Problem
Yellowing grass is a symptom, not a disease in itself. Your lawn is telling you something is wrong — usually with nutrition, water, or soil structure. Before reaching for a product, run through these six common causes to pinpoint the real issue.
Nitrogen deficiency
The most common cause. Grass starved of nitrogen turns pale yellow-green across the whole lawn. Fix with a spring/summer fertiliser high in nitrogen (e.g. 9-7-7).
Drought stress
During dry spells, grass shuts down and turns yellow-brown. It's usually dormant, not dead — deep watering brings it back.
Dog urine patches
Scorched yellow circles with a dark green ring. The high nitrogen in urine burns the grass. Flush with water and reseed.
Soil compaction
Hard, compacted soil starves roots of oxygen and water. Grass yellows in high-traffic areas. Aerate to relieve it.
Iron deficiency / chlorosis
Yellowing with green veins often means iron deficiency, common in alkaline or waterlogged soils. Use a high-iron fertiliser or iron sulphate.
Lawn disease
Fusarium patch and red thread cause localised yellow patches, often in damp, humid conditions. Improve drainage and airflow.
The Solution
Once you've identified the cause, the fix is usually straightforward. Here's the step-by-step approach for the most common scenario — nutrient deficiency:
Confirm the cause
Walk the lawn. If the whole lawn is evenly yellow-green, it's nutritional. If it's patchy, look for urine spots, compaction, or disease rings.
Aerate compacted areas
Use a garden fork or hollow-tine aerator on hard, yellow patches. This lets water and nutrients reach the roots.
Apply the right fertiliser
For general yellowing, use a balanced spring/summer feed like Nutrigrow 9-7-7. For iron deficiency, choose a high-iron product. Apply with a spreader for even coverage.
Water it in
Water thoroughly after feeding (or apply before rain). Nutrients need moisture to reach the roots. Avoid feeding during drought — feed once soil is moist.
Reseed bare patches
Where grass has died back completely, rake out dead material, loosen the soil, and overseed with a quality UK grass seed blend.
Use the Fertiliser Calculator
Work out exactly how much fertiliser you need for your lawn area — no guesswork, no waste.
Recommended Products
Browse fertilisers formulated to green up yellow lawns, from balanced NPK feeds to high-iron treatments.
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