Dogs are a mans best friend but when it comes to lawns they can and will damage it.
One of the top questions we get asked is how do I fix yellow spots or patchy grass that has been damaged by dog urine.
Why does it happen?
Grass turns yellow when exposed to ammonia from urine. Ammonia is an odourless gas produced by the breakdown of urea (the main nitrogenous waste product of animals) in the soil. It is also found in some fertilizers.
In essence it is like dumping some highly concentrated fertiliser right onto your lawn. This will "burn" your grass.

Is there a way to prevent it?
Obviously the easiest solution is to prevent your dog from urinating on the grass - this is easier said than done. You can water the spots your dog uses as soon as possible after he urinates there. If you've watered them enough, the spots will turn green. If you haven’t, the spots will go yellow and start dying.
Alternatively you can just wait and see. Often the grass will recover all on it's own, it may take a few weeks but this depends entirely on the type of lawn you have, rainfall and so many other variables.
You should also encourage your dog to drink lots of water to avoid having concentrated pee.
Dogs need to eat a lot of water to stay healthy. Pups who eat dry food tend to drink less water than dogs fed wet food. To prevent lawn damage, you should feed your dog wet food instead of dry food. You should also watch out for signs of dehydration, such as dark yellow or brown urine.
How to fix yellow grass from dog urine:
If your grass is already yellow it is too late to prevent it from happening. So how exactly do you repair the yellow grass?
- You could wait and see: Often grass will recover all on it's own. This depends entirely on the current health of your lawn.
- Repair with grass seed: The only sure fire way to repair yellowing grass is to replace it with new green grass. Rake the area and put a handful of grass seed down, cover with top soil and in a week or two you'll have nice, fresh green grass.
There is no miracle product that will turn yellow grass into green grass, save your money.
You have to either wait and see or use a fast growing grass seed to repair the damage.
How to fix dead grass patches caused by dog urine
If your grass does not recover after turning yellow there really is only one solution - you need some grass seed to repair the patchy area, dead grass won't come back to life.
Patchy lawns can be susceptible to weeds, bare soil is an open invitation for weeds to infest your lawn so be sure to fix those patchy areas fast!
Here's what you'll need:
- A rake for removing any dead grass or moss and loosening the top layer of soil
- Some topsoil, get screened top soil, Do not use compost! Top soil is available from every garden centre and is relatively cheap.
- Some fast growing grass seed. Don't just buy the cheapest you can find, you want fresh, fast growing seed for the best results.
Once you have everything it is a relatively easy job depending on how large the patchy areas are.
- Use your rake and vigorously rake the patchy area removing any dead grass & weeds. This should also loosen the top layer of soil allowing your seed to put down good roots.
- Put down your grass seed taking care to evenly spread across the patches.
- Cover with topsoil and gently flatten. Ensure the seeds have good contact with the soil.
- Water in well with a fine spray or rose. In dry conditions ensure the area stays damp. Grass seed doesn't like dry conditions and your seeds won't germinate if it's too dry.