Butterflies are brilliant pollinators and add vibrancy and colour to the garden. But over the past forty years, they have gone through a precipitous decline as a result of habit loss, climate change and the use of pesticides. Whether you have a window ledge in the city or a country garden, there is a lot you can do to make your green patch butterfly-friendly. Find out which nectar-rich blooms to grow, and when and where to plant them.