Shallots (Allium cepa var. aggregatum) are a cultivar group of the common onion, known for their delicate, mild, and sweet flavor. Unlike onions, which typically form a single large bulb, shallots are “multiplier” onions. Each planted bulb, or set, naturally divides to form a cluster of new bulbs throughout the growing season. Successful cultivation requires proper site selection and timing to ensure the clusters develop fully.
Site Preparation and Optimal Planting Timing
Shallots thrive in full sunlight, ideally receiving at least six hours of direct sun daily. The ground must offer loose, well-draining soil, as waterlogged conditions quickly lead to bulb rot. Amending the planting bed with organic matter, such as compost or manure, improves both fertility and drainage.
The soil pH should be slightly acidic to neutral, targeting a range between 6.0 and 7.0. Before planting, incorporate compost into the top six to eight inches of the bed to provide nutrients for the shallow root systems. Shallots can be planted in either fall or spring, depending on the climate and desired harvest size.
Fall planting, typically done after the first frost, allows the bulbs to root over winter and results in a larger yield harvested in early summer, especially in milder climates. Planting in early spring, as soon as the ground is workable, is the most common method in regions with severe, prolonged winters. Spring-planted shallots mature within 90 to 120 days, ready for harvest in late summer or early fall.
Determining Spacing and Planting Depth
Because of their multiplier nature, proper spacing is necessary to maximize the size and health of the final clusters. Each planted set will develop a cluster of five to twelve new bulbs, requiring sufficient room to expand underground. Plant individual sets four to six inches apart within the row to allow for this horizontal growth.
Rows should be spaced between 12 and 18 inches apart to allow for air circulation and easy access for maintenance like weeding. This wider spacing helps prevent fungal diseases and ensures the foliage dries quickly after irrigation or rain. Ample space directly influences the final size of the harvested bulbs; closer spacing results in many smaller bulbs, while wider spacing yields fewer, but larger, shallots.
Place the shallot sets with the root end down and the pointed tip facing upward. Planting depth is very shallow; the goal is to just cover the bulb, leaving the tip or neck slightly exposed or level with the soil surface. Planting too deep hinders the division and expansion of the bulb cluster. This shallow placement also encourages the development of a papery skin suitable for long-term storage.
Essential Post-Planting Maintenance
Shallots are shallow-rooted plants requiring consistent moisture throughout their active growing season for proper bulb formation. They need approximately one inch of water per week. Water deeply when the top few inches of soil become dry, especially during low rainfall. Avoid overwatering, as overly soggy soil quickly leads to bulb rot and disease issues.
Weed control is important because shallots do not tolerate competition well, and weeds steal water and nutrients from the shallow root system. Weed carefully by hand or with very shallow cultivation to avoid disturbing the newly forming bulb clusters. Applying a light layer of organic mulch, such as straw or grass clippings, helps suppress weeds and conserve soil moisture.
Shallots benefit from a light application of nitrogen-rich fertilizer early in the season to support robust leaf growth. This side-dressing is typically done about 30 days after planting, or when the leaves reach a few inches in height. Stop all fertilization once the bulbs begin to swell. Excessive nitrogen late in the season encourages foliage growth at the expense of bulb development and reduces storage potential.
Harvesting and Curing Shallots
Knowing the precise moment to harvest is important for achieving the best flavor and storage longevity. Shallots signal readiness when the foliage begins to turn yellow, brown, and naturally fall over. This usually occurs in mid-to-late summer, approximately 90 to 120 days after spring planting.
Once the tops have collapsed, carefully lift the bulbs from the soil using a garden fork to avoid damaging the clusters. After removing excess soil, the shallots must be cured by placing them in a warm, dry, and well-ventilated area, away from direct sunlight. Curing involves completely drying the outer skins and necks, a process that typically takes two to three weeks.
The curing process is necessary for long-term storage, as it allows the outer wrapper to tighten and seal the bulb, preventing moisture loss and the entry of pathogens. Once fully cured, trim the dried tops and roots before storing the bulbs in a mesh bag or slatted crate. Cured shallots store best in a cool, dry, and dark location with good air circulation, remaining viable for several months.