Nettles grow all year but it's only in Spring and Autumn that their leaves are small and tender. Nettle grows around road sides, waste areas, walk ways and river. I'm sure if you looked you would find some. When cutting them wear thick rubber gloves and cut off the tender tips and small leaves. Nettles when simmered in water at around 50°C lose their toxic sting and becomes similar to spinach, and can be prepared in many dishes instead of spinach. The sauce below is excellent with the pasta but it also goes well with tomato and seafood sauces or just toss it with a little olive oil or butter and mixed herbs.