Brown / Yellow Patches

Brown / Yellow Patches on Lawn

• Animal Urine

  Signs & Symptoms:
  

  Circular brown patches on lawn grass with outer rings of longer, very bright grass in areas that your pets (or other animals) may use to relieve themselves.

  
  Cause:
  

  This is a common problem caused by animal urine, especially bitches. If you do not have any pets, it may be that you have a vixen (female fox) visiting your garden.

  
  Solution:
  

  Irrigate the affected area after each visit and, in future, encourage your animal to use an area other than the lawn. You may want to consider using dog rocks in your pet’s water bowl to neutralise urine. In extreme cases, dig out and replace the soil and turf or seed.

• Petrol or Oil Spills

  Signs & Symptoms:
  

  Random / irregular patches of dying brown grass appearing across large areas of the lawn or running in lines across it.

  
  Cause:
  

  This may be caused by petrol spills or oil leaks from a lawnmower or other machinery.

  
  Solution:
  

  Do not fill your mower while it is on the lawn as petrol spills can kill grass. The soil will need to be heavily and regularly irrigated and over seeded. In extreme cases, dig out the dry patches on your lawn, replace the soil and sow fresh seed.

• Tree Roots

  Signs & Symptoms:
  

  You might notice brown patches on the lawn grass under the canopy of trees, particularly when weather is dry/hot in summer.

  
  Cause:
  

  The tree roots may be competing with the grass for moisture. Brown patches mean that the lawn is losing the battle.

  
  Solution:
  

  Aerate to ventilate and improve drainage in the soil. In severe cases, water the lawn in the morning so the grass doesn’t need to compete for ample moisture with the surrounding trees.

• Chemicals and Cleaning Agents

  Signs & Symptoms:
  

  Regularly-spaced, boot-sized areas of dying grass or brown patches on lawn.

  
  Cause:
  

  This can occur when someone has walked over a driveway or patio area that’s been treated with path cleaner (or other chemicals) and then walked across the lawn.

  
  Solution:
  

  Wear wellington boots or similar while using chemicals and wash them before walking on the grass. Walking on your lawn after several days of heavy frost or drought can also cause dry patches to appear later in the year.

• Brown Stripes

  Signs & Symptoms:
  

  Lines of brown grass on lawn surface, usually after feeding. These are interspersed with areas of bright green grass.

  
  Cause:
  

  Feeding your lawn with the wrong range of nutrients, excessive fertiliser or harsh chemicals can scorch the lawn and, in some cases, kill the grass. Either the fertiliser has not been applied in the correct dosage, or the wrong equipment has been used.

  
  Solution:
  

  Prevention is easier than the cure, so take care when measuring and applying anything you put on your lawn, and make sure you’re not double-dosing certain areas by overlapping the application runs. To get rid of brown stripes, irrigate and aerate the lawn, overseeding when necessary.

• Bare Patches on High Spots

  Signs & Symptoms:
  

  Bare spots or yellow patches on lawn that end up being colonised by moss and/or weeds.

  
  Cause:
  

  If your lawn is uneven, your mower blades may scalp the grass (cutting too close to the ground) on high spots. This can weaken or even remove the grass in these areas. Rotary mowers are especially prone to this.

  
  Solution:
  

  Raise the height setting of your lawnmower blade. Take action to remove extreme undulations from your lawn in order to avoid scalping. Top dressing can help to even out undulations.

• Colour Change After Mowing

  Signs & Symptoms:
  

  During the summer, your lawn starts to turn yellow – and some areas turn almost white – within a few days of mowing.

  
  Cause:
  

  Cutting the grass in very dry weather removes moisture. If the weather remains hot, dry and (worst of all) sunny, the grass will become stressed and lose moisture, resulting in yellow patches on lawn surface. Additionally, blunt mower blades can smash the grass and leave tears/bruising, which can allow disease to enter the grass blade. Irregular or infrequent mowing will also stress the grass, particularly if you allow it to grow quite long and then cut it short.

  
  Solution:
  

  Sensible watering – and timing your mowing properly – should prevent this problem from occurring. Plenty of irrigation will help the grass recover if it’s already happening. Make sure your mower blades are sharp, and adopt sensible mowing habits: only cut the grass when it needs cutting, try not to mow in frosty or very dry weather, and remember the 1/3 rule (never cut off more than one third of the grass’s length at any given time).

• Excessively Thick Thatch

  Signs & Symptoms:
  

  Random visible areas of brown grass on the surface of the lawn. These brown patches may have a spongy feel when you walk on them.

  
  Cause:
  

  Excessive thatch on the lawn will retain water, holding it on or near the surface and creating humid conditions that can encourage certain diseases. The thatch keeps moisture from being absorbed by the soil and reaching the roots of the grass, therefore the grass dies and turns brown.

  
  Solution:
  

  To prevent brown patches from forming due to excessive thatch, water must be allowed to reach the roots. Lawn scarifying can remove the thatch and moss. Aerate if possible.

• Soil Compaction

  Signs & Symptoms:
  

  Brown patches on lawn in areas of heavy foot traffic or on heavy clay soils. When it rains, the water sits on the surface and doesn’t drain away.

  
  Cause:
  

  Compacted soil is preventing water from soaking into the soil and stopping moisture reaching the roots.

  
  Solution:
  

  Aerate or spike to relieve compaction and increase the flow of water to the soil and roots. In serious cases, top dress with sandy top dressing to improve soil quality and improve ventilation.

• Turf Diseases

  Signs & Symptoms:
  

  Numerous small circular brown spots spreading and multiplying quickly (particularly during periods of warm weather) and gradually increasing in size.

  
  Cause:
  

  There are several different turf diseases that can lead to brown patches on lawn grass. Some of these diseases can be caused by feeding your soil with the wrong type of fertiliser; some are encouraged when there is too much nitrogen in the soil. Turf diseases are also encouraged if the soil is poorly nourished and/or heavy with thatch.

  
  Solution:
  

  Aerating and a programme of correct feeding with appropriate balanced feeds will solve most minor cases. Moderate to extreme cases may require an application of fungicide. Reducing the frequency of mowing in moist damp weather prevents the spread of turf diseases and reduces stress on the grass. Regular aeration and scarifying will remove thatch and help to prevent repeat problems.

• Insect Damage

  Signs & Symptoms:
  

  Brown patches have appeared in areas near walls, fences, and other locations with damp and/or shady conditions. The size and number of patches may be increasing rapidly.

  
  Cause:
  

  The larvae of various insects (e.g. chafer grubs, leatherjackets) eat the roots and shoots of your grass. Large areas of your lawn can be damaged beyond repair if you are not quick to take action against an insect infestation. Birds – especially larger species – pecking at your lawn for the grubs/larvae are an indication that you may have an insect problem.

  
  Solution:
  

  Lawn & Weed Expert can identify and treat insect problems safely and effectively with the relevant pesticide. This service is cost-effective an available throughout South Wales – see our pest management page for more information.

• Drought

  Signs & Symptoms:
  

  Grass loses its shine and starts to look dull and brown.

  
  Cause:
  

  This is caused by a lack of moisture due to low rainfall or competition from nearby trees/shrubs.

  
  Solution:
  

  All living things require moisture. Give the lawn a thorough watering to help it recover. Water in the morning so that the grass will have time to dry out before humid conditions begin to take hold. Avoid watering at night.

• Leaves

  Signs & Symptoms:
  

  Yellow patches on lawn (and eventually dead grass) appear during the autumn.

  
  Cause:
  

  Allowing leaves to rest on your lawn – even for just a few days – can cause serious damage. Leaves should be swept up every 3-4 days. If the grass does not receive any light for more than 6-7 days, it will begin to deteriorate.

  
  Solution:
  

  Regularly sweep or blow away your leaves during the autumn.

• Moss

  Signs & Symptoms:
  

  The lawn turns yellow-green, with areas of thin, sparse, weak grass.

  
  Cause:
  

  Heavy clay soils tend to suffer from moss problems. The moss competes with the grass for nutrients and moisture, gradually weakening and pushing the grass out.

  
  Solution:
  

  Treat moss with an effective moss control agent. Depending on the amount of moss present, this may need to be followed up with scarifying to remove the dead moss and aeration to resolve soil compaction, which is one of the underlying factors that can allow moss to develop. Next, use a 70% sand-based top dressing to improve soil quality. Finally, overseed to thicken the grass.

• Waterlogged / Poorly-Drained Lawn

  Signs & Symptoms:
  

  A sticky covering of paste-like soil on the surface of the lawn.

  
  Cause:
  

  Compaction caused by steady, regular footfall (even animal traffic) can combine with heavy rainfall to create slow-draining areas of lawn that hold water and form puddles.

  
  Solution:
  

  Relief can be achieved via lawn aeration and spiking to a depth of 4 inches, followed with top dressing. Filling the holes with sandy top dressing allows them to act as mini ventilation shafts, improving the flow of water and air to the roots. Ideally, work should be carried out in the autumn as opposed to the spring, and a rich feed of potassium used to assist root development. Severe cases will require some land drainage – aerating and top dressing will only improve surface drainage, not drainage as a whole.

• Worm Casts

  Signs & Symptoms:
  

  Brown bubblegum-type smears across your lawn, or small mounds of damp earth.

  
  Cause:
  

  Some earthworm species dig out and secrete earth onto the soil surface. The resulting deposits are called casts, and they can be smudged / smeared by lawnmowers or feet.

  
  Solution:
  

  Let the casts dry and brush away with a stiff yard brush. The Lawn & Weed Expert team can, if appropriate, spray a product onto your lawn that will discourage worms from excreting deposits and thus prevent worm casts.