All willow outside will need to be treated. The traditional treatment is Boiled Linseed Oil and Turpentine (or Turpentine substitute), in a 50:50 mix. This can be painted on with a brush or using a hand pump sprayer. Annual treatment is recommended. There are waterbased treatments available, such as Protek Clear Tough Coat. Aftercare can be provided if required.
Where possible seats should be placed under cover in winter.