Keep watering them and give them a bit of fertiliser to build up the bulbs ready for next year. Once they die down naturally, knock them out and store in a cool dark place ready to replant in Oct/Nov. Did that with mine last year that were in pots and replanted at allotment where they all flowered again. You can also plant any little bulblets that have appeared and grow them on to produce more flowering bulbs in a few years.
