I grow willow on the Black Isle and also cut willow at Diabaig on the West Coast. I grow a variety of S. purpurea as well as S. viminalis 'Continental' and S. alba 'Chermesina'. I can supply a mixture of S. purpurea 'Packing Twine' and 'Brittany Blue' at 3 - 6 foot lengths. This gives a subtle variation in colour when dry.
Growing willow in South Lanarkshire, varieties Carl Jensen, Bleu, Brittany Green, Daphnoides I usually harvest in February and welcome volunteers who can help themselves to cuttings material. Otherwise I can sell cuttings.