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  • Which bulbs do I need to chill?

    Some flowering bulbs need winter chilling in order to bloom in spring. Bulbs native to tropical or Mediterranean climates do not.

    What is “chilling”?
    In mild, temperate climates, gardeners who wish to grow bulbs needing a period of cold temperatures need to simulate a cold, dormant period. We do that by “chilling” them—placing them in a refrigerator (not the freezer!) for approximately eight weeks. Afterwards, they are planted just as you would in any climate.


    Which bulbs?
    In California, bulbs needed this type of chilling are tulips, hyacinths and spring-flowering crocuses.


    How to chill
    Purchase them in October and place them in your refrigerator in a paper bag (not plastic) where they will not freeze. You must also avoid placing ripening fruit in your fridge while your bulbs are chilling. Fruits give off ethylene gas which is harmful to bulbs.


    When to plant
    After about eight weeks of chilling, plants the bulbs outside in the ground or in pots following the depth guidelines for each. A perfect time in mild California climates is between the Christmas and New Year holidays or as late as the first couple of weeks in January. You’ll have a gorgeous show of flowers come spring.


    Will they bloom next year?
    Bulbs that are artificially chilled will not come back the next year, nor are they strong enough to dig up and chill again. Think of them as you would an annual flower—they’re worth it! They put on a great seasonal show.


    Click Here iconLearn about planting Fall bulbs >

    Click Here iconLearn about Bearded Iris, a popular Fall Bulb choice >

    See more articles about: Bulbs