Here are various flower bulbs that are planted in spring.
Note that Crocosmia, Ranunculus and Nerine can easily overwinter outside.
Crocosmia or Montbretia blooms in midsummer. Ranunculus blooms in early summer. Nerine is a slow starter, but blooms profusely in late summer until frost. Nerine is also a great cut flower that lasts a long time in the vase.
