By Emma Mackenzie If you have roses in your garden, never throw this kitchen scrap away again. This humble bit of kitchen waste could actually be the key to transforming your rose bushes, but most people simply throw it away unknowingly. The nutrient-rich scrap is a common sight, but you might not realise that by chucking it in the bin you’re missing out on seriously elevating your rose bushes. For many keen gardeners in the UK, roses are the absolute centrepiece of their green space. With blooms available in pretty much every shade, delicate petals, a range of sizes, and stunning fragrances -…