I have found the answer to my problem at last - for those like me with a dog that leaves pee burns on the lawn behind them I must share 'The Natural Green Grass Patch' with you all natural green colourant that you simply spray on and the brown is gone - GENIUS - we have tried rocks in the past hoping to prevent them occurring - but now I don't feel embarrassed about friends looking at the garden as the unsightly patches no longer stick out like a sore thumb... I bought it on Amazon well worth it if you want to see green and not a polka dot lawn I highly recommend it :-)