Most experts recommend lifting the bulbs before first frost. Ideally the leaves will have died back naturally, but you can cut back the foliage if needed. Dry the bulbs in a well ventilated, warm, dry space for a few days. Then store in a flat open box with dry peat moss. Bulbs can also be stored in pantyhose bags with peat moss. Keep the stored bulbs where the temperature does not fall below 65ºF.