How should I harvest and store garlic?
Gauging the right time to harvest is very important. Garlic will double in size during its last stage of growth. If dug too soon, the cloves will not have grown to their maximum size. If bulbs are dug too late, they may have begun to split apart in the soil.
While some producers begin harvesting when the leaf tips start to brown, others use the number of green leaves left on the plant to judge if the bulb is ready, and harvesting when about six plant leaves are still green. Some growers harvest when plants are 40 percent browned and 60 percent green. However, leaf conditions cannot always be an accurate indicator that it is time to harvest. Browning of leaves may be the result of drought, damage, or disease. A good approach is to dig up some plants up to determine the correct time to harvest. The outer skin should be tight, the bulbs fully developed and well formed. Consider digging sooner rather than later. If garlic becomes too mature before harvest, the cloves will begin to crack apart while still in the ground. However, if the garlic is pulled at a slightly immature stage, the leaves, which serve as wrappers for the cloves, will continue to translocate nutrients to the cloves, making the crop easier to prepare for sale.
In small-scale plantings, garlic can be dug with a garden fork. For larger acreages, several tools are available for undercutting and harvesting garlic. Bed lifters, potato diggers, or subsoilers can be used to loosen garlic from the soil. (These will not work if heavy mulch remains.)
After mechanical digging, the garlic still needs to be removed from the field by hand. Field grading should be done immediately to remove any damaged or diseased plants, a standard practice for disease prevention. Sort garlic into three categories:
- Small bulbs can be cleaned for sale or your own kitchen.
- Medium-sized bulbs are cleaned in preparation for sale.
- Large bulbs are saved for planting stock. These should not be washed, but hung in a covered barn or shed to dry. Fans may be used to increase air movement in wet years.
Before garlic is stored, it must be properly cured or dried, usually for at least 10 to 14 days. The neck cells constrict and hold the juice in the bulb. This can be done with the stem and roots still on, but there are many theories on this which can vary by region and year. After a couple of weeks, they may be clipped off, leaving ¼ to ½ inch of the stem and roots. When the outer skins are dry and crispy, the garlic is ready for storage or sale. It can be stored in clean onion bags. Garlic will lose up to 20 percent of its weight in the curing process. It is important to keep temperature and humidity constant. High humidity will keep the bulbs from dehydrating. A walk-in cooler should make a suitable storage facility; however, many farms shut their coolers down in the winter. Also, any variation or fluctuation in these conditions will initiate sprouting. This can make it difficult to store garlic for long periods of time without sprout inhibitors. A 25-watt light bulb and a thermostat can be used to provide heat when needed. A fan will keep air circulating.
Ready to learn more? Check out the ATTRA publication Garlic: Organic Production. It addresses most aspects of organic garlic production, including seed sources, organic fertility management, pest management, and harvesting and storage. Marketing and economic considerations, including enterprise budgets for organic garlic production, are also addressed.