Non-chilling Flower Bulbs
Spring-blooming bulbs naturally go through a period of chilling during winter, which will cause dormancy. The warmer temperatures of spring force the embryonic plant inside to wake up and begin growing. Summer bloomers don’t require this cold period and tender varieties may even be killed by exposure to cold temperatures. For this reason, many of the bulbs need to be dug up and held indoors in winter to ensure their viability for the next season. There are many types of plants that flower and flourish in summer, but bulbs provide a unique spectrum of form and color that accents the usual perennials and annuals in the flower bed. Summer bulbs are planted in spring after all danger of frost has passed. Spring bulbs need temperatures of at least 40 degrees Fahrenheit (4 C.) to force them out of dormancy, but this isn’t the case with the summer flowering types. Since they are bulbs that don’t need chilling, they are the best bet for a gardener that forgot to plant bulbs in the fall.
Which Bulbs Do Not Require Chilling?
Now that we have established that there are two season types of bulbs with different temperature needs, it is time to wonder which bulbs do not require chilling. Some very common non-chilling bulbs are amaryllis and paperwhites. These are commonly grown as houseplants around Christmas and Hanukah but can also be planted outdoors in suitable regions. Crocosmia is fairly hardy and is a summer bloomer that doesn’t need a cold period. Agapanthus is a stunning and regal blue flowering bulb, while Hymenocallis abounds with large mid-season white flowers. Additional examples of bulbs that don’t need chilling include:
Gladiolus Ismene oriental lilies (Peruvian daffodil) Pineapple lily Caladium Butterfly ginger Anemone Allium Crinum lily Fairy wand Turks Cap Oxalis
Cold Treatment for Bulbs
If you have your heart set on tulips, narcissi, crocus, or other early-season blooming bulbs, you may need to provide a cold treatment for bulbs to sprout. Summer blooming varieties are good for forcing bulbs without chilling, but the spring types need a cold period followed by warmth to break dormancy. The method for forcing bulbs without chilling is simply to start them indoors in pots with a good bulb mixture or equal parts soil, peat, and perlite. Plant the bulb with the pointed end up and the flatter end at the bottom of the hole. Spring-blooming bulbs need little more than a warm location inside and average water. Spring bloomers require the cold treatment, and forcing bulbs without chilling will result in soggy bulbs in a pot. Most spring bulbs will come pre-chilled, but if you have over-wintered them indoors, it is easy to mimic the cold period. Place the bulbs in peat moss and refrigerate them for three months, then bring them out and gradually let the bulbs warm for a couple of days before planting them.
