Bring Back the Green
Yellow grass is usually hungry grass. Our seasonal lawn treatments deliver exactly what your lawn needs to recover its colour and build lasting health – not just a quick cosmetic fix.
A yellow lawn is trying to tell you something. The good news is that yellowing grass is almost always fixable once you identify the cause. The bad news is that there are quite a few possible causes, and treating the wrong one wastes time and money.
Here’s how to diagnose why your lawn has turned yellow – and exactly what to do about each cause.
The Most Common Causes of Yellow Lawns
Yellow grass typically comes down to one of these issues: lack of nutrients, water problems (too much or too little), physical damage, or environmental stress. Let’s work through each one.
1. Nutrient Deficiency
This is the most common cause of a uniformly yellow lawn – especially in spring when grass is growing fast but soil nutrients are depleted after winter.
What it looks like: The whole lawn (or large areas) turns pale yellow-green. Older leaves yellow first. Growth slows noticeably.
Why it happens: Grass needs nitrogen to produce chlorophyll (the green pigment). Without enough nitrogen, grass can’t make enough chlorophyll and turns yellow. This is particularly common in lawns that haven’t been fed, or where heavy rain has washed nutrients out of the soil.
The fix: Apply a lawn feed appropriate for the season. You should see improvement within 1-2 weeks. For ongoing prevention, feed your lawn 3-4 times per year – spring, summer, autumn, and optionally winter.
2. Drought Stress
When grass doesn’t get enough water, it goes into survival mode – and one of the first signs is yellowing.
What it looks like: Grass turns dull yellow-brown, starting in the most exposed areas. Footprints stay visible after walking on the lawn (grass doesn’t spring back). The soil feels dry and hard.
Why it happens: Without water, grass can’t take up nutrients or maintain normal cell function. It shuts down and goes dormant to survive. Extended drought causes the leaf blades to die back, though the roots and crown usually survive.
The fix: Water deeply once or twice a week rather than little and often. If the lawn has gone fully dormant, don’t panic – it will usually recover when rain returns. Avoid fertilising drought-stressed grass; wait until it’s actively growing again.
3. Overwatering and Poor Drainage
Too much water causes as many problems as too little – possibly more.
What it looks like: Yellowing often with a spongy, soft feel to the lawn. Moss may be present. The soil stays wet for days after rain. You might notice a musty smell.
Why it happens: Waterlogged soil pushes out air, and grass roots need air to function. Without oxygen, roots suffocate and can’t take up nutrients – even if those nutrients are present in the soil. Root rot and fungal diseases often follow.
The fix: Improve drainage. Aerate the lawn to create channels for water and air. For severe drainage problems, you may need to add sand to the soil or install drainage. Stop watering and let the soil dry out.
4. Fertiliser Burn
Too much fertiliser causes chemical burn that turns grass yellow or brown.
What it looks like: Yellow or brown patches, often with distinct edges corresponding to where fertiliser was applied heavily or overlapped. Sometimes you’ll see a “stripy” pattern following spreader tracks.
Why it happens: Concentrated fertiliser salts draw moisture out of grass roots through osmosis. This is the same process as salting a slug – the salts pull water out and the tissue dies.
The fix: Water the affected areas heavily and repeatedly to flush the excess fertiliser through the soil. Several deep waterings over a few days should help. For severe burn, you may need to overseed the bare patches once the area has recovered. Always follow application rates and calibrate spreaders properly.
5. Dog Urine
Dog urine is essentially a concentrated nitrogen fertiliser – and too much nitrogen in one spot burns grass.
What it looks like: Circular yellow or brown patches, often with a ring of lush green grass around the edge. The green ring is where the diluted urine fertilised the grass rather than burning it.
Why it happens: Dog urine is high in nitrogen and salts. In small amounts it fertilises grass; in concentrated amounts it burns it. Female dogs and large dogs cause more damage because they deposit larger volumes in one spot.
The fix: Water the area immediately after your dog urinates to dilute the urine. For existing damage, water heavily, wait for the area to recover, and overseed if necessary. Some people train dogs to use a designated area, or use dog-friendly grass seed that’s more resistant to urine.
6. Mowing Too Short (Scalping)
Cutting grass too short causes yellowing – and it’s one of the most common lawn care mistakes.
What it looks like: Yellowing immediately after mowing, or yellowing that follows a pattern matching mower passes. Often worse on uneven ground where the mower dips and cuts too low.
Why it happens: When you cut grass too short, you remove most of the leaf tissue that produces energy through photosynthesis. The plant can’t sustain itself and the remaining tissue yellows. You also expose the pale lower stem that hasn’t seen sunlight.
The fix: Raise your mowing height to 3-4cm for most lawns. Never remove more than one-third of the grass blade in a single cut. The lawn will recover within a few weeks if the roots are still healthy.
7. Compacted Soil
Compacted soil prevents grass roots from functioning properly, leading to general decline and yellowing.
What it looks like: Gradual yellowing, often in high-traffic areas. The soil feels hard when you push a screwdriver into it. Water pools on the surface rather than soaking in.
Why it happens: Compacted soil has no air spaces for roots to breathe or grow into. Water and nutrients can’t penetrate. The grass slowly starves even if you’re feeding it, because the roots can’t access anything.
The fix: Aerate the lawn to relieve compaction. Hollow-tine aeration (removing plugs of soil) is most effective. You should see improvement within a few weeks as roots recover.
8. Shade
Grass in heavy shade often turns yellow and thin because it can’t get enough light.
What it looks like: Yellowing and thinning specifically in shaded areas under trees, beside buildings, or under overhangs. The grass looks stretched and sparse.
Why it happens: Grass needs light for photosynthesis. In heavy shade, it can’t produce enough energy to maintain healthy growth. Most common lawn grasses need at least 4 hours of direct sunlight.
The fix: Improve light levels where possible (prune overhanging branches, remove obstacles). Reseed with shade-tolerant grass varieties. Mow shade areas slightly higher (4-5cm) to give grass more leaf surface for capturing limited light. Accept that some areas may be too shady for grass and consider alternatives like ground cover plants.
How to Diagnose Your Yellow Lawn
Ask yourself these questions to narrow down the cause:
Is the yellowing uniform or patchy?
Uniform yellowing → Likely nutrient deficiency or drought
Patchy yellowing → Could be dog urine, fertiliser burn, compaction, or disease
When did it start?
After mowing → Probably cutting too short
After fertilising → Probably fertiliser burn
During hot, dry weather → Probably drought
Gradual over time → Could be nutrient deficiency or compaction
What does the soil feel like?
Dry and hard → Drought or compaction
Wet and spongy → Overwatering or poor drainage
Where is the yellowing?
High-traffic areas → Compaction
Shaded areas → Lack of light
Spots where the dog goes → Urine burn
Everywhere → Nutrient deficiency or environmental stress
For more troubleshooting guides and lawn care advice, visit our complete UK lawn care guide.
Frequently Asked Questions
Will yellow grass turn green again?
Usually, yes – if you address the underlying cause. Grass that’s yellowed from drought, nutrient deficiency, or light stress will recover. Grass that’s completely dead (brown and crispy throughout) may need overseeding to fill in.
How long does it take for yellow grass to recover?
Typically 2-4 weeks once you’ve fixed the problem. Nutrient deficiency responds fastest (you’ll see greening within 1-2 weeks of feeding). Drought recovery depends on how severe the stress was.
Should I water yellow grass?
It depends on the cause. If the yellowing is from drought, yes – water deeply. If it’s from overwatering or poor drainage, no – let it dry out. If it’s from fertiliser burn, yes – water heavily to flush out excess salts.
Can I fertilise yellow grass?
Only if the yellowing is from nutrient deficiency. Don’t fertilise drought-stressed grass (wait until it’s actively growing), waterlogged grass (roots can’t take up nutrients anyway), or grass suffering from fertiliser burn (you’ll make it worse).
Why is only part of my lawn yellow?
Patchy yellowing suggests a localised problem: dog urine, fertiliser overlap, compaction in high-traffic areas, shade from trees or buildings, or drainage issues in low spots. Identify what’s different about that area compared to the healthy parts.
Ready to restore your lawn’s colour? If nutrient deficiency is the cause, our seasonal lawn treatments deliver exactly what your grass needs to green up and stay healthy through the year.
