If you'd like to transplant existing flower bulbs, such as daffodils, from one area of the garden to another, it's generally best to do so right after they go dormant.
The best time to dig up spring-flowering bulbs is roughly six weeks after they finish blooming. At this point the foliage will have yellowed and withered (if it hasn’t, wait longer), but you can still see it. This makes locating the bulb easy, so there’s less of a chance of damaging the bulb as you dig. Also, 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.
Once you've dug them up, you can either replant the bulbs right away or store them until fall planting time. If you store the bulbs, place them in mesh or paper bags in a cool, dark place. Do not seal the bags.
As long as you can easily locate the bulbs, you can also dig them up in fall and transplant them immediately.
Summer-flowering hardy bulbs, such as lilies, should be dug and moved in early autumn after their leaves have turned yellow. Don’t delay getting them back into the ground—these cannot be allowed to dry out.
