Dog & Bitch Urine
Though large dogs can rip a lawn to shreds when playing the main cause of lawn damage comes from their urine.
There is an element of truth in the old wives tale that bitch urine is more harmful. The fact is the ladies squat and deposit urine in one large dose whereas the fella’s go round spraying a bit here and a bit there to mark their territories. This means there is usually an insufficient amount from the male to cause much damage.
The urine is a highly concentrated nitrogen liquid not too dissimilar to ammonia or bleach. Remember: nitrogen is also a fertiliser! So, poor a cup of bleach on to your lawn and you’ll soon get a dead brown patch just as if the dog had peed! It’s the concentration that is deadly NOT the chemical, just like a bottle of wine is not lethal but a bottle of Stolichnaya might be!
Now, if you put a small cup of bleach into a watering can of water and watered a few square metres of lawn you’d end up with lovely lush green grass….. completely the opposite of dead because you’ve diluted it!
The problem is the same for bleach as it is for dog urine. Initially the concentration is so high that they both act as poisons and therefore the grass dies within days. A week or so after the dead patch has formed you’ll notice a green ring of tall lush grass surrounding it. This is because the urine has become diluted with rain or ground water and as the urine contains nitrogen (a fertiliser) it now starts feeding the grass.
Dilution is the Solution!
Stopping the dog peeing may be impractical so you have two options to prevent urine burn:
Keep your eye on the dog when it first goes on to the lawn and pour a bucket of water on to the place where the dog pees to dilute the urine.
Better still keep a high level of moisture in the lawn where the dog pees. During dry spells, put the sprinkler on once or twice a week for an hour. Then when the dog goes to the toilet the urine will dilute very quickly due to soil moisture thus reducing most of the damage.
I’ve heard of people putting tomato juice on to the dogs food or putting ‘Dogrocks’ into the dogs water to reduce the urine burn but I can’t find any proof that they work. Do you know differently? Let me know so we can pass on the advice.
Tip: It also helps if you keep the lawn as healthy as possible by feeding every spring and autumn and mow weekly on the high side. Use the middle to top height settings on your mower only.
New Lawns - New Seed
If you're starting a new lawn with pets in mind then you can reduce the effect of urine burn to some degree but first let me dispell the myth: there is no grass that is genetically able to withstand the effects of concentrated doses of urine - full stop.
If as above there is sufficient moisture in the soil to dilute the urine then you'll have some resistance to burn; OR if the roots are so deep that the urine doesn't get down to them then you will also reduce the damage. If you have both a moist soil AND deep roots you're on to a winner and little Toto can go peeing to his or her hearts content!
The seed you need is our Staygreen.
Dead Patches from Urine Burn
If you’re reading this because the damage is already done then hopefully the above helps with reducing future damage. Existing dead urine burn patches, less than two inches across will more than likely grow over in a month or two. If the patches are bigger or you want to speed recovery in smaller patches:
- Rake out the dead grass
- Prick the soil surface about 1cm deep with the garden fork
- Lightly sprinkle in grass seed that matches your existing lawn; about 10 – 20 seeds per square inch, no more
- Tread the surface to firm
- Water lightly and at least daily for the first 2 weeks