When Will My Spring Bulbs Bloom?

Snowdrops – “Heralds of Spring“

Answering the question, “when will my spring bulbs bloom?” may take a little explaining. Spring bulbs grow and bloom when warmer temperatures arrive. They only form flowers if they have undergone the proper chilling period to break dormancy. In most of the country, October is the best time to plant spring bulb flowers. This allows the bulb a chilling period of 12 to 15 weeks, which is necessary for spring bulbs to sprout. Spring bulb flowers need to experience temperatures of 35 to 45 degrees Fahrenheit (1 to 7 degrees C.) for up to 15 weeks.

The time for bloom after chilling varies by species. Tulips need 10 to 16 weeks of chilling and will sprout 1 to 3 weeks after the required period. Crocus, grape hyacinth and daffodils have similar spouting times, but crocus and grape hyacinth need 8 to 15 weeks of chilling and daffodils 12 to 15 weeks. Snowdrops can begin blooming 2 weeks after chilling and need 15 full weeks of cold temperatures. Iris and hyacinths need 13 to 15 weeks of chill period and will also sprout 1 to 2 weeks after the requirement is fulfilled.

Gardeners often worry when they see daffodils, tulips and other spring bulbs emerge long before it’s spring; but you need not fret or worry because there’s little cause for concern. Spring-blooming bulbs prefer old-fashioned winters, when soil temperatures drop gradually, stay cold and then gradually warm up as spring approaches. But even with today’s more erratic winter weather, bulbs are proving to be remarkably resilient.

Tulips, daffodils and other fall-planted bulbs begin growing almost as soon as they are planted. During the late fall and early winter season, bulbs are developing their root systems and already starting to sprout. If the weather is unusually warm, these sprouts may rise to the soil surface and show a few inches of green.

This overly eager foliage can be damaged by extreme cold and drying winds, and may cause the tips of the leaves to turn brown. As long as the flower buds stay below ground, they are well protected from cold. If they rise above the soil surface, you can add a layer of mulch to help protect them.

One thing you can do however is cover the soil surface with mulch after you plant in the fall. Several inches of mulch will provide good protection from extreme cold. It also keeps the soil temperature constant and shields premature sprouts from damage. The best time to apply a winter mulch is late fall, after the ground starts to freeze.