Lilies can still be planted if the weather and soil are suitable.
When buying from a store, choose plump, healthy looking bulbs and avoid dried-up specimens. Some otherwise good bulbs arrive in an over-dry condition. Revive these bulbs by setting them in trays of slightly damp peat in a frost-proof place, then potting them prior to planting out.
  Some lilies will already be coming through in the garden. Use cloches to protect the shoots from frost. Many autumn-flowering lilies are the first to appear, while some early-flowering lilies appear surprisingly late.
Under glass
Sow seed under glass.
  Many of the imported lily bulbs now on sale make splendid pot plants. Pot them in John Innes potting compost No. 1. using plenty of drainage material in the bottom of the pots. A 6 in. pot will hold three small lilies such as L. pumilum, or one medium-sized bulb such as 'Enchantment'. An 8 in. pot will accommodate three medium-sized lilies, or one large one such as L. auratum.
  Plant stem-rooting lilies with the base of the bulb only 2 in. above the drainage material to leave space for adding soil around the stem roots.
  When buds appear on forced lilies, raise the temperature to 18-21ºC (64-70ºF). Feed weekly with dilute liquid manure until the buds are ready to open. Most forced lilies flower six weeks after the appearance of the buds.