Expert: Kenneth Joergensen - 10/27/2003

Question
will callalillys and tulips grow here? i think i am in zone 9. thank you vicki

Answer
calla lilies are tender bulbs which are damaged at temperatures below 25 deg F and will do just fine in zone 9 if planted outdoor the entire year.

Tulips can be planted in late winter if the bulbs have been pre-cooled prior to planting. pre-cooling can be done by growers or you can do it yourself by storing the bulbs in the fridge.  Bulbs require 8 to 10 weeks of "Precooling", i.e. dry cold storage at 40 to 45°F in an ethylene-free refrigerator prior to planting.  These are subsequently planted in late November and December. Ethylene is created with ripening fruit (apples, tomatos, etc) or cut flowers are stored in the fridge. if you plan on storing bulbs in the fridge then keep ripening fruit out.

When planting spring and early flowering bulbs in USDA Climatic Zone 9 the bulbs should be planted in an area that does not receive direct sunlight from late morning to early afternoon.  This helps to moderate the prevailing temperatures and provide a more suitable microclimate.


Tulips which has been precooled (aka "forced") are usually not reusable and should thus be treated like annuals. After flowering you can pull the bulb and plant up and discard. buy and plant new bulbs next fall.