We have just bought a house that came with a garden of Tiger Lillys and Irises. Can you please tell me what regimen is required to maintain them; if and when to prune the folliage etc?

The irises and the lilies are very easy to look after and will survive in almost any soi.l. If you wish to trim the foliage I suggest that you do it in the early spring at which time you can also divide any clumps that you wish to and move to another location. However when the flowers are finished blooming trim off the flowers as the plants will give all their energy to producing seeds instaead of enery to the plant for next year.