What are Chilling Requirements for Plants?

July 16, 2018

A chilling-hour requirement is a safety mechanism plants employ so they don’t produce flower buds too early, potentially losing their flowers (and thus fruit and seeds) to cold or freezing temperatures. The plants keep a memory log of the amount of chilling time they have experienced at the right temperatures to trigger the flowering process.

I must replant new prechilled tulip bulbs in my Texas garden each December. ‘Maureen’ is a reliable favorite.
PC: Leslie F. Halleck

Tulips, hyacinth, hardneck garlic, columbine, foxglove, and stone fruits like peaches, apples, and cherries are just a few examples of plants that require vernalization. If these plants don’t receive the necessary chilling time, they won’t flower, set fruit, or develop bulbs.

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