Gardening advice travels strangely. A tip passed down from a grandparent, a rule of thumb repeated often enough to feel like fact, a technique that someone saw work once and has since elevated to gospel. The internet has accelerated this considerably, surrounding genuinely useful guidance with a thick sediment of received wisdom that ranges from mildly unhelpful to actively counterproductive. Some of it is harmless. Some of it costs money. Some of it kills plants. Here are eight of the most persistent garden myths, and what actually happens when you examine them honestly. Myth 1: You need a big garden…