Growing oriental lilies from seed requires some patience. Wait until the seed heads have turned brown before collecting the seeds. Its best to sow them straight away into damp compost and cover with a further sprinkling of compost. Cover the containers with cling film/polythene bags it will help to retain moisture. Keep them warm between 15-21 centegrade is a good temperature. Keep them at this temperature for 3 or 4 months then move them to your fridge for at least 3 months. If any have sprouted after 3 or 4 months, move them into a bright place to grow on, the rest should be put in the fridge. By time they are finished in the fridge, it will be late spring/early summer and the perfect time to place them outside in a cold frame or in the ground. Growth will be small the first year and it may take a few years before plants produce a flower.