Become one of the best young gardeners in the country and why can you hear the sea in shells?

Rachel Godfrey from the Royal Horticultural Society joins Dan in the studio to chat all things gardening - what's easy to grow, what we can grow to eat in a couple of months and how you can become school gardener of the year. 

Plus, Professor Hallux explains why we can hear the sea in seashells, we find out how touch screens work with Techno Mum and was the Black Death really spread by rats? Some scientists are questioning it.