A dry patch of grassYellow and dry patches on your lawn can be caused by everything from grubs to dry spells – getting to the (sometimes literal) root of the issue can prove difficult for frustrated gardeners. But if your yellowing or black, dry, and generally burnt-looking grass appears after mowing, the Royal Horticultural Society (RHS) thinks the answer might be a simple one. Though weedkillers and pesticides can sometimes create limp, weak grass – especially if they’re overused – a little mindless mowing may accidentally be leaking another harmful chemical onto your lawn too. If you’ve just started your springtime mowing, the problem may be to blame for any new, random dead patches.The issue could be down to petrol leaks