Most bulbs prefer not to be disturbed and can be left in
the ground for many years. But beware of overcrowding. When
too many bulbs try to occupy the same space, they will be
less vigorous and flowers will be fewer and smaller, an
indication that it's time to transplant them.
Spring - Once the foliage dies back or
matures in late spring or early summer, the bulb is
dormant. You can tell the plant is dormant when the foliage
is brown and papery and can easily be pulled free. Summer
is the dormant period for spring
bulbs. As the foliage dies back, the roots that nourish
the bulbs also die back. With fall rains, the bulb comes
out of summer dormancy and roots begin to grow again to
provide the bulb with nutrients and moisture. Once spring
bulbs enter dormancy, the time is right to dig the
bulbs if needed. Some bulbs benefit from digging to divide
them and spread them out over the bed.
If you lift your spring-flowering bulbs, they should be stored in a well-ventilated
place and replanted in the fall. Every five years, daffodils and crocus
should be dug and replanted to prevent overcrowding. The
first signs of overcrowding will be a decrease in flower
size and uneven plant height. When this occurs, dig, spread
your bulbs and replant immediately.
Summer - Less hardy bulbs such as dahlias and begonias should be lifted each fall. It is best to lift after
frost has blackened foliage; gently spade up the bulbs,
being careful not to cut into the bulbs/tubers and damage
them. If you prefer to lift the bulbs before it frosts, you
can dig your bulbs early and store them in a
well-ventilated, frost-free area until dry. Allow leaves to
remain on bulbs until they also become dry.
Most bulbs should be dried for about a week before you
prepare them for storage. Remove any remaining foliage,
shake bulbs gently to get rid of any clinging soil and dust
them with fungicide powder to prevent rot. Place them in
unsealed paper bags or old nylon stockings with some dry
peat moss to keep bulbs from touching one another. Store
them away from sunlight in a cool, dry basement, cellar,
garage or shed at 16° to 18°C. Avoid temperatures below
10°C or above 21°C unless different storing instructions
are given for particular bulbs. Follow specific storing
instructions for tender bulbs such as dahlias and begonias.
800-644-5505
Summer - Less hardy bulbs such as 
Planting and Care of
Bulbs: 
