This study aimed to identify the optimal winter storage temperature for preserving bulbil vigor and enhancing the efficiency of spring bulbil cultivation in garlic. Bulbils from the cultivars ‘Daeseo’ and ‘Hongsan’ were categorized into three size grades (#1: <3 mm; #2: 3–4 mm; #3: 4–5.5 mm) and stored for five months (September 2024–February 2025) under four conditions: conventional warehouse storage, 4°C, 15°C, and 25°C. The bulbils were sown in rows in an open field on 20 February 2025 and harvested on 30 May 2025. After curing for 2–3 days and air-drying for about one month, the harvested bulbs were evaluated for the number and characteristics of round bulbs. For both ‘Hongsan’ and ‘Daeseo’, storing bulbils in either a conventional warehouse or at 4°C during winter resulted in higher harvest rates. Larger bulbils consistently produced a greater number of harvested bulbs and heavier bulb weights. In ‘Hongsan’, only the #3 bulbils stored at 25°C yielded a small proportion ( 1. 2%) of multi-clove bulbs, while a ll o ther treatments resulted in single-clove bulbs exclusively. Mean bulb weight was lowest after storage at 25°C and tended to be higher under warehouse storage. In ‘Daeseo’, there was no significant difference in harvest percentage between warehouse and 4°C storage; however, the mean harvest percentage was higher and the variation among replicates was lower at 4°C. Notably, multi-clove bulbs were observed only with warehouse storage (#2: 0.35%; #3: 1.8%), while 4°C storage resulted exclusively in single-clove bulbs. Mean bulb weight increased with bulbil size across all treatments, and conditions that produced more multi-clove bulbs generally also showed heavier mean bulb weights. Overall, for spring cultivation of bulbils, 4°C storage is optimal for enhancing single-clove bulb production in ‘Daeseo’, while conventional winter storage is sufficient for ‘Hongsan’.