Patchy lawns are rarely caused by one single issue. More often, they’re a sign that a number of smaller things aren't quite right. These can include mowing the grass too short, waterlogging, heavy use, nutrient deficiency and hot, dry summers. Patches can also happen if areas of lawn are in the shade and competing with overhanging trees or dwarfed by tall buildings that block out sunshine and light.
“Patchy lawns are usually a sign that something small has gone out of balance rather than a major problem,” says Chris McIlroy, lawn expert at The Grass People. “Grass is surprisingly resilient, but it still relies on the basics being right, namely light, air, nutrients and space for roots to grow. When one of these is missing, patches tend to show up first.”
After speaking to a range of lawn experts, I discovered the top 6 causes that are the most common reasons you're seeing patches in your lawn. Follow their advice and put lawn care at the top of your to-do list now to boost your grass ahead of summer.
Article continues below1. Moss build-up
A common cause for a patchy lawn is moss suffocating the grass, which prevents water and nutrients from reaching the roots. During summer, when the weather is dry, moss then dies back, leaving behind unsightly patches on your lawn. Moss can also take hold in shady areas of the garden where it tends to thrive.
"Moss is usually a sign the grass isn’t thriving," says Cheryl Harper, managing director of Greensleeves Lawn Care. "This is often due to shade, damp conditions, compaction or thatch build-up. Once moss is removed, it can reveal bare patches underneath, making the lawn look worse before it improves."
How to fix it
Remove moss thoroughly, usually by scarifying the lawn or raking it out along with excess thatch. "Then focus on improving the conditions grass needs," advises Cheryl. "Aeration reduces compaction, drainage improvements stop the lawn staying wet for too long, and reducing shade helps grass outcompete moss. Once the surface is clear and conditions are better, overseeding the lawn fills the gaps and helps prevent moss from returning."
Cheryl Harper is the managing director of Greensleeves Lawn Care. Established in 1998, Greensleeves is a lawn care franchise that delivers a year-round service through an extensive network of franchisees across the UK.
Remove moss and improve your lawn's health
This adjustable lawn rake is ideal for removing a build up of thatch and moss from your lawn as well as autumn leaves later in the year. The telescopic handle can be extended to a number of different lengths, and although it's made from heavy-duty materials it's also lightweight to use.
Designed to be used from April to September, this 4-in-1 lawn treatment can help to kill weeds and moss to boost the overall health of your lawn. By encouraging stronger roots it can help it withstand hotter temperatures in summer.
If your lawn is in need of some extra help, this electric scarifier is designed to remove dead grass, moss and leaves as well as aerate the soil. It has four cutting depths, a 32cm working width, a 30L collection bag and 10m cable.
2. Waterlogging and poor drainage
In spring and autumn heavy rainfall can wreck your lawn, leading to unsightly bare patches. This is a particular issue if you have poorly draining clay soil or need to trek across your lawn regularly to the shed or vegetable garden, further churning it up. It can be hard for your lawn to adapt to conditions like this but there are things you can do to rectify the situation.
How to fix it
Make sure the grass is well-fed and healthy, as the longer the root system is, the more water the lawn can absorb on its own. Check for moss in the lawn too, as this acts like a giant sponge.
Reduce compaction by forking the lawn and top-dress with sand. If these steps don’t solve the problem it might be time to put drainage in your garden. Lawns that need better drainage benefit from grass reinforcement grids that create a cellular structure beneath the grass to aid drainage while also protecting the root system.
3. Lack of nutrients (or too much fertiliser)
Like any other plant, grass needs nutrients to survive. If a lawn lacks essential nutrients, it may begin to show signs of stress, such as brown, yellow or patchy spots. Conversely, applying too much fertiliser can scorch a lawn, which can also cause it to look patchy and discoloured.
"Grass needs a consistent supply of nutrients to stay healthy, but patchiness can appear when lawns are underfed or when fertiliser is applied incorrectly," says Chris McIlroy, lawn expert at The Grass People. “Without the right nutrients, grass can look weak and uneven, but too much fertiliser, as well as applying it in hot weather, can scorch the lawn."
How to fix it
Fertilise a lawn by feeding it little and often, choosing the right product, and watering it in properly helps avoid yellow or brown patches.
Westland's child and pet-friendly lawn care from Amazon is an organic fertiliser with added lawn seed and can be used to cover an area of 400 square metres.
Chris McIlroy is a lawn and seed specialist at The Grass People, with a passion for helping people grow healthier, better looking green spaces. With years of hands-on experience Chris is known for turning the science of grass into straightforward, practical advice. Chris supports product development and customer guidance, helping to deliver reliable results.
4. Hot, dry summers
Extended dry weather is one of the most common causes of thin or patchy lawns, particularly when watering is restricted as lawn grass can develop severe dehydration. This is known as heat stress, and one of the early signs is grass turning brown.
"This is the first stage of self-protection for the grass as it begins to put all its resources and energy into its root system to stay alive," explain grass experts Luke Taylor and Mark Kerr, founders of So&Me, and authors of the new book Lawns: An Uncomplicated Guide. "A healthy lawn that has been regularly fed and well maintained will bounce back incredibly quickly from heat stress."
How to fix it
Once temperatures start to fall after a hot spell, water the lawn and apply a feed. "To prevent heat stress in the first place, you need to undertake quite a regimented watering programme to ensure the lawn doesn’t dry out and start to wilt," say Luke and Mark. "This might be twice a day, depending on weather conditions."
They also suggest using a feed containing a wetting agent like this premium one by the Striking Lawns Store from Amazon to protect your lawn from drought and reduce the impact of heat stress. Additionally, a wetting agent will also help the lawn to bounce back much quicker if it does feel the effects of a hot summer.
"Wetting agents are, as the name suggests, designed to help to manage water in the lawn and are beneficial during summer when rainfall decreases, long periods of heat are common, and the plants start to develop heat stress," they say.
Marc Kerr comes from a world of building and maintaining some of the best golf courses in the UK and elsewhere. Marc trained to be a professional greenskeeper before moving to the USA in 2002 to enrol on the Ohio State Turf Program, which focuses on the environmental, aesthetic, recreational and economic benefits of turf grass. Luke Taylor’s journey has involved everything from residential gardening to landscaping. In 2017 Luke joined All Turf, a specialist turf supplier to the golf and landscaping industry. He eventually launched the construction arm of the company along with Marc, as they started to build and maintain extremely high-end private lawns and grass projects. Luke and Marc founded So & Mo together in 2020.
5. Dog damage
From digging holes to leaving brown spots, dogs can cause a lot of damage to your lawn. Dog urine is high in nitrogen, which can scorch grass and leave yellow patches, particularly from female dogs.
One way to prevent damage is to include some dog-friendly garden ideas in your space by creating a designated area in the garden for your pet. You can also opt for tough grass species like dwarf perennial rye, as they tend to be more hard-wearing. It's also a good idea not to let dogs out in the garden first thing in the morning, when urine is at its most concentrated. Instead take them for an early walk.
How to fix it
"Start by removing any dead grass and debris from the area," advise Luke Taylor and Mark Kerr. "Once cleared, loosen the soil with a rake and add a layer of top dressing. Then, sprinkle grass seed over the area and lightly cover it with more topsoil. Be sure to water the area regularly and keep it moist until the new grass begins to grow."
Alternatively, replace damaged patches by laying turf. "To do this, start by cutting out the damaged area with a spade or turf cutter. Then, level the soil and lay the new turf in place. Be sure to water the area regularly and keep it moist until the new turf takes hold. This method is more expensive than re-seeding, but is effective for larger areas of damage."
6. Lawn wear and tear
If your lawn is a well-used, high-traffic area it can end up looking threadbare, especially if children and dogs are out there playing games on it all year round. This can result in patchy and compacted areas, and in some cases sections that are completely bare.
"Lawns aren’t indestructible, and repeated footfall in the same areas gradually wears the grass down, compacting the soil," says Cheryl Harper. "Over time, this creates thin, bare patches where grass struggles to recover."
How to fix it:
Aerating the lawn helps relieve compaction by creating small holes in the soil, allowing air and water to reach the roots again. "Once the ground is opened up, raking out dead material and overseeding helps rebuild density and encourages grass to knit back together," says Cheryl. "If possible, reducing repeated wear – for example with stepping stones or temporarily resting the worst patches – gives new grass the chance to establish properly."
You can also try rejuvenating grass with a lawn thickening product. "Perfect for boosting tired lawns, patches or even new lawns, Johnsons Lawn Thickening with Seedbooster® available from Amazon, is child, pet and environmentally friendly," says lawn expert Guy Jenkins from Johnsons Lawn Seed. "Meanwhile Johnsons Quick Fix, also available from Amazon, is a blend of Growmore, NPK 7-7-7 fertiliser and Amenity Dwarf Perennial Ryegrass, suitable for lawns with high traffic."
Guy Jenkins is Consumer Manager for DLF Seeds Ltd and Johnsons Lawn Seed. Established in 1820, Johnsons Lawn Seed is the oldest lawn seed brand in the UK, and dedicated to research and development. All products have been developed as part of a 15-year breeding and R&D programme. As a result, gardeners can rest assured that every single seed that fills its boxes has been carefully researched, evolved and selected to create the perfect lawn.
When is the best time to repair a patchy lawn?
Reseeding will be one of the most effective ways to repair a patchy lawn, but it's important to do it at the right time.
"When it comes to when to reseed a lawn, the key is to avoid extremes," says lawn expert Guy Jenkins. "If it's very cold in March or April or there is a run of frosts or snow it is best to avoid sowing grass seed. Low ground temperatures prevent germination and frost can kill freshly emerging shoots. It's better to wait for the weather to warm up.
"It's equally important to avoid high temperatures. Periods of hot sun and warm wind will dry out and kill emerging shoots even if they have been watered the evening before. Instead, pick a time when it's more likely to be mild and damp.
"Sow grass seed when the ground has had a chance to warm up. Avoid extremes of temperature and rainfall. Late summer and early autumn often provide the ideal conditions when the ground is warm and there is frequent rain."
As a final point, it's important to note that while mowing is a key task in your lawn care calendar, improper mowing can also lead to bare patches of lawn. Dull mower blades can rip and shred the grass rather than cut it cleanly, while cutting the grass too short can scalp the lawn, causing stress that leads to patchiness. You should also avoid cutting wet grass for the same reason.
