Stages of Growth – Garlic is day-length sensitive • No control over when garlic starts to make bulbs, only over how large and healthy the leaves are when bulbing starts, and how large the final bulbs can be. • Bulbs start forming and no more leaf growth happens once day-length exceeds 13 hours, with air temperatures above 68°F (20°C) and soil temperatures over 60°F (15.5°C) as secondary triggers. • 12 hours of daylight on the spring equinox. After that, the farther north you go, the longer the daylength is. Northern latitudes reach 13 hours of daylight before southern ones, but garlic does not start bulbing there at 13 hours because temperatures are not yet high enough. Temperatures cause harvest dates to be earlier in warmer zones than in cooler areas at the same latitude. • It is important to establish garlic in good time so roots and leaf growth are as big as possible before the plants start making bulbs. Small plants on the trigger date will only make small bulbs!