Are Lilium difficult the answer is no; given the right conditions Lilies will be happy and most will happily naturalise. Lilium make excellent garden plants and are ideal for pots, because some soil conditions are not good for lilies grow them in pots and place in the herbaceous border between shrubs and perennial plants.
Asiatic Lily Group are not scented and pollen free, they have a large colour range than some of the other groups from pure white, pink, yellow, dark red to almost black, the flowers tend to be more upward facing and are quiet hardy, plant were they can be left undisturbed. Asiatic lilies like alkaline soil.
Oriental Lily Group bring there heady fragrance to the garden, there flowers are large and wide the colour combination is not as varied as the Asiatic group they tend to be white, pink to deep carmine red. There is now a new range of double Orientals Miss Lucy is a delightful pure white with a pink flush. Oriental lilies like acid soils if planting in pots use ericaceous compost.
Orienpet Lily Group is a combination of Oriental and Trumpet Lilium, fragrant and very tall with a good colour range from white, pink, yellow, red and orange, the longer this group is left undisturbed the taller they become you sometimes see them advertised as tree lilies, they can grow as high as 7ft and are ideal for the back of the border.
Trumpet Lily Group have wide, large trumpet shaped flowers with a heady perfume they tend to be tall, Regale is one of the best know in the trumpet group with it’s pure white flowers with magenta flush on the reverse of the petals, plant and leave undisturbed they take little feeding and will be fine in poor soil.
Specie Lily Group contain the stalwarts of the garden, they tend to be Turk’s cap with downward facing flowers, Lilium Martagon and Lilium Martagon Album although expensive are worth the outlay they will happily self seed and will reward your investment over the years they can produce over 30 flowers per stem. The Specie group of lilies like dappled shade although they will take the sun, provide them with acid to neutral soil and leave undisturbed.
Longifolium Lily Group they tend to be white but pink is becoming more available, these are the classic long white trumpet lilium, they are fragrant. They like alkaline to neutral soil.