This prevents premature growth as the sun warms the soil. For good bulb growth and rebloom the following year, do not disturb foliage until it begins to yellow. Cut off all faded foliage. Braiding the foliage is not recommended. Some bulb plants must be dug and divided periodically to retain plant vigor.
Some lilies can increase so rapidly that division is necessary.
Divide and transplant during the dormant period. Many of the minor bulbs, such as snowdrops, multiply readily without loss of quality. They are used in the landscape to fill in as ground cover and in naturalized areas. In the case of tulips, bulblets form at the expense of the parent bulb. This causes flower size to decrease and eventually, the bulb ceases to flower.