Flowers grown from bulbs produce some spectacular blooms in the garden from early spring until late summer. But, just like flower and vegetable seeds, bulbs have a built-in time clock that dictates when they will bloom. For whatever reason, a gardener can miss the optimum time to plant bulbs for the best result, but all is not lost. Bulbs can be very forgiving.
Spring-blooming bulbs, like crocus, daffodils and tulips need a period of cold to break them out of the dormant stage. Therefore, most spring-blooming bulbs are planted in late fall, before the ground freezes. If the ground is already frozen to the extent that you cannot dig into it, it is too late to plant the bulbs, and the bulbs will need to be stored in a cool, dry location and planted as soon as the ground is thawed enough to dig in the late winter or very early spring.
Planting spring bulbs late in the spring may produce leaves, but no blossoms or very scraggly looking blooms.
Summer-blooming bulbs include gladiolas, lilies, dahlias and alum and can be planted up to mid-summer. If you plant a summer-blooming bulb too late in the summer season, it will probably grow and produce leaves but will not have the right conditions, or enough developing time, to bloom that year.
What to Do With Late-Planted Bulbs
For spring-blooming bulbs that were planted too late for the bulb to produce a healthy blossom, leaving the bulb planted to go through its dormant cycle until the following spring is advised. If it is a warmer, no-freeze area, you may wish to dig the bulbs up and store them in a dry, cold area or refrigerator until the correct time to plant for the next year.
Summer-blooming bulbs in warm regions can be left in the ground to go dormant and reappear the next summer, yielding normal, beautiful blossoms. In milder climates, bulbs left in the ground are considered perennials. In colder regions, depending on the bulb, you may need to dig summer-blooming bulbs up before the ground freezes and store in a cool, dry place over the winter months. Gladiolas are one such bulb that will not survive over the winter in frozen soil, while many lily bulbs can tolerate the frozen ground with no difficulty.
The bottom line is: If you have planted bulbs too late for sufficient blooming one year, simply wait until the following year for normal blooming and a spectacular display.