Most garden furniture comes from the oil-heavy hardwoods of Teak, Roble, Cumaru, Courbaril and Eucalyptus. The nature of the wood means that furniture can be left out all-year-round with only a soapy wood scrub-down required on an annual basis to remove algae and debris.
Cracking along the grain is perfectly normal for any hardwood item and the furniture will usually fade to a beautiful soft silver grey. If you want to keep some colour in the wood, scrub down the furniture and allow to dry out properly. Apply a teak cleaner, followed by a teak brightener and finish off with teak oil. Never apply teak oil to damp or wet wood.