Jerusalem artichokes, often called sunchokes, are robust root vegetable tubers native to North America. This perennial plant, a relative of the sunflower, is known for its high productivity. The edible portion is the knobby underground tuber, which stores its energy primarily as inulin, a type of carbohydrate. To maximize the sunchoke’s naturally sweet flavor and improve its texture, the timing of the harvest is important.
The Optimal Timing Window
The most significant factor in developing the best flavor in Jerusalem artichokes is exposure to sustained cold temperatures. Harvesting should be deliberately delayed until late in the growing season, specifically after the plant has experienced the first hard frost.
Cold temperatures initiate the conversion of inulin, the plant’s primary storage carbohydrate, into fructose, a simple sugar. This process, known as cold-induced sweetening, improves the tubers’ sweetness and reduces their starchy texture. The visual signal indicating the tubers are ready is the complete dieback of the tall, leafy stalks above ground, which typically occurs from late October to December, depending on the specific climate.
In temperate regions, the ideal harvest window extends from late fall, after the foliage has fully withered, through early spring. Many growers choose to leave the tubers in the ground throughout the winter months, treating the soil as a natural storage medium. Harvesting can then be done as needed, provided the ground is not frozen solid, often continuing until the new spring growth begins to emerge.
Practical Steps for Harvesting
Before beginning the harvest, all the dead stalks should be cut down to just above ground level. This step clears the work area and prevents the long, withered stems from interfering with the digging process. A garden fork or pitchfork is the tool of choice for excavation, as using a shovel can easily slice and damage the irregularly shaped tubers.
The tubers grow erratically, often spreading several feet from the main stem and sometimes reaching deep into the soil. To avoid impaling the crop, the fork should be inserted into the ground at least 12 to 18 inches away from the base of the cut stalk. By gently leveraging the fork, the entire clump of tubers and roots can be lifted from the soil as a single mass.
Once the main cluster is removed, the remaining soil should be carefully turned over and sifted by hand. This secondary search is necessary because many smaller tubers will have broken off or grown independently of the main root ball. Any small pieces missed during the harvest will remain in the ground and sprout the following spring, ensuring the continuation of the crop.
Post-Harvest Handling and Storage
Jerusalem artichokes have a thin, delicate skin that offers little protection against dehydration, causing them to dry out rapidly once removed from the ground. Unlike potatoes, sunchokes do not benefit from a curing process and require immediate handling to maintain their moisture content. The tubers should not be washed until they are ready for use, as excess moisture promotes spoilage during storage.
Instead of washing, gently brush off the loose dirt and soil from the tubers. For short-term storage, placing the unwashed sunchokes in a perforated plastic bag in the refrigerator’s crisper drawer is effective, where they can last for a few weeks. For longer preservation, the tubers thrive in an environment that is cool, dark, and humid, ideally between 32°F and 40°F (0°C and 4°C).
A common long-term method involves layering the tubers in a container filled with slightly damp sand, peat moss, or sawdust, then storing the container in a root cellar or cold basement. This technique mimics the moist soil environment, preventing shriveling and allowing the sunchokes to remain viable for several months.