Why is vernalization critical for artichokes?
Written by
Liu Xiaohui
Reviewed by
Prof. Charles Hartman, Ph.D.Vernalization (q.v.) is necessary for artichokes, which is essentially a process in which the exposure of the bulbs to cold stimulates the development of the buds in the plants. Otherwise, the plant continues to produce only leaves, and no edible buds will form.
Physiological Triggers
- Cold exposure activates flowering genes in meristem tissue
- Breaks dormancy by altering hormone balances
- Stimulates carbohydrate conversion for bud formation
- Increases frost tolerance through cellular adaptation
Temperature Requirements
- Optimal range: 40-50°F (4-10°C)
- Minimum effective duration: 10 consecutive days
- Avoid temperatures below 35°F (2°C) to prevent damage
- Monitor soil temperature for root vernalization effects
Climate Adaptation
- Enables annual production in zones 5-8
- Compensates for insufficient natural chilling hours
- Allows container plants to flower in warm regions
- Critical for first-year harvests with modern hybrids
Start outdoor vernalization once frost danger has passed, place seedlings in a shady situation, where night temperatures hover around 45°F. (7C).... When cold snaps come unexpectedly, with temperatures dropping below 35°F. (2C) Cover the plants with mats. Although this method produces stronger plants than would otherwise have been made, it necessitates close "weather-watching". I note microclimate conditions with wireless thermometers.
Refrigerator method Best-kept plants can be placed on the middle shelves of ventilated containers, but avoid placing them directly on cold surfaces, as frigid temperatures may cause them to freeze, which is disastrous. Keep at 40 to 45°F (4 to 7°C), and have trays of moist sand or towels, as the atmosphere is arid. Examine daily for signs of condensation.
Incomplete vernalization. Symptoms: Few buds are produced. Cause: Insufficient chilling in the soil of the plants' roots; or, the treatment was too brief. Cure: Extend the treatment another 3-5 days if bud initiation has stalled; check that the temperature of the soil is sufficiently cold. After treatment add some phosphorus to the media to cause flower blooms, used about half strength of follar fertilization.
Read the full article: How to Grow Artichokes Successfully
