The best time to dig up spring-flowering bulbs is about six weeks after they….

Finish blooming. When the foliage has died back you can still see it, which makes locating the bulb easy. There’s less chance of damaging the bulb if you can find it easily. By waiting until after the foliage dies, you ensure that the leaves have done their job of replenishing the bulb’s nutrient stores through photosynthesis.