Garlic propagation relies on saving vegetative material, often mistakenly called “seeds” in common gardening language. True garlic seed, the product of sexual reproduction, is exceedingly rare in cultivated Allium sativum. Gardeners primarily save cloves, the segments of the underground bulb, or bulbils, tiny aerial clones produced on the flower stalk of hardneck varieties. Both offer a reliable path to a new crop but require different harvesting and storage methods. Saving the largest cloves is the standard and most efficient method for ensuring a healthy, genetically identical harvest the following year.
Storing Garlic Cloves for Planting
Saving planting stock begins at harvest by selecting only the largest, firmest, and most symmetrical bulbs, ensuring they are free from blemishes or disease. These superior bulbs are reserved for replanting to pass on the best traits. The size of the planted clove directly correlates with the size of the resulting bulb, making this selection process fundamental for saving good stock.
After harvest, the entire plant must undergo a curing process, drying the bulbs, stalks, and roots for approximately two to six weeks. This should occur in a well-ventilated space, such as a covered porch or barn, protected from direct sunlight and rain. Curing is complete when the outer wrappers are dry and papery, the neck is constricted, and the central stem is brittle and hard. This drying phase seals the bulb, protecting it from moisture and pathogens during long-term storage.
Once cured, the bulbs require cool and dry storage conditions that will not trigger premature sprouting. Ideal conditions for preserving planting stock are a temperature around 50°F (10°C) and a relative humidity of 65 to 70 percent. Storing the bulbs too cold can inadvertently break dormancy, leading to undesirable sprouting before the fall planting time.
The bulbs should be stored whole, with wrappers intact, in breathable containers like mesh bags, perforated crates, or open baskets to allow for continuous air circulation. Adequate airflow prevents moisture buildup, which encourages mold growth and decay. Storing garlic in a dark location, such as a basement or pantry, also helps prevent premature sprouting, ensuring they remain dormant until fall planting.
Harvesting and Saving Bulbils
An alternative method involves saving the small, teardrop-shaped bulbils that form in the umbel atop the scape of hardneck garlic varieties. To harvest bulbils, the scape must be left on the plant to mature, which diverts energy and results in a slightly smaller underground bulb harvest. Bulbils are ready for collection when the plant begins to die back and the surrounding papery sheath of the umbel has dried and split open.
After harvest, the bulbils must be separated from the chaff and dried thoroughly in a sheltered, well-aerated location for several days. Once dried, bulbils can be stored similarly to cloves, kept in a paper or mesh bag in a cool, dry location until the fall planting season. This aerial propagation material is naturally disease-free, offering an advantage over soil-grown cloves, which may harbor pathogens.
Planting a bulbil produces a small, single-clove bulb known as a round in the first year. These rounds must be replanted for a second season to develop into a mature, multi-clove bulb. This two-to-three-year maturation timeline makes planting cloves the preferred method for an annual harvest. However, bulbils are valuable for multiplying rare varieties or creating disease-free stock.
Preparing Saved Stock for Planting
Before the saved cloves or bulbils can be planted, they must be prepared to ensure a successful start to the growing season. The most important step is vernalization, a process of cold exposure that is necessary for the plant to properly differentiate and form a multi-clove bulb. Hardneck varieties, in particular, require a chilling period of six to eight weeks at temperatures between 35 and 45°F (1–7°C) to break dormancy.
If a gardener lives in a region without sufficiently cold winters, this chilling must be simulated by placing the whole bulbs in a refrigerator for the recommended duration. The bulbs should be stored in a paper or mesh bag during refrigeration to maintain airflow and prevent moisture accumulation, which can cause mold. Separating the cloves from the bulb should be delayed until just a few days before planting to prevent them from drying out or deteriorating.
Some growers use a pre-planting soak to disinfect the cloves before they enter the soil. A common disinfection method involves briefly soaking the separated cloves for 10 to 20 minutes in a 3% hydrogen peroxide solution or a high-proof alcohol like vodka. This step sterilizes the surface of the clove, reducing the risk of transmitting common fungal diseases or mites.
After any soaking treatment, the cloves should be planted immediately in the fall, approximately four to six weeks before the ground freezes solid in the region. This timing allows the cloves to establish a robust root system before the onset of winter dormancy. The established roots will then be ready to fuel rapid leaf growth as soon as temperatures warm in the spring, maximizing bulb size the following summer.