Countryfile's Plant Britain by the Sea special shines the spotlight on the incredible coastline of our island and how we can all do our bit to help combat climate change, revive the fortunes of our wildlife and boost our own mental wellbeing. Matt Baker launches Countryfile’s Coastal Clean Up initiative while Ellie Harrison helps to sew meadows out at sea and discovers the miracle properties of seagrass. Charlotte Smith goes on the hunt for rare dune plants saved from the brink of extinction, John Craven finds out how helping our coast to be in the best of health is also remedying young people’s eco anxiety, and Tom Heap investigates the importance of protecting our sand dunes.