8 Supplies for Harvesting and Curing Storage Onions

Late summer brings the satisfying sight of a fully matured onion bed, but pulling bulbs from the ground is only half the battle. A successful harvest requires turning those juicy, field-fresh globes into rock-hard, shelf-stable storage staples that will last straight through the winter. Having the right tools on hand ensures every bulb cures cleanly without bruising, rotting, or succumbing to excess moisture.

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Recognizing When Storage Onions Are Ready to Pull

Timing the harvest correctly directly dictates how well storage onions will keep through the colder months. When onions approach maturity, the foliage stops receiving nutrients from the roots, causing the cell walls in the neck to weaken and collapse. A bed is ready for harvest when roughly 50 to 75 percent of the tops have naturally fallen over.

Resist the temptation to manually bend green tops over early to force ripening. Prematurely knocking down vigorous foliage interrupts natural bulb swelling and creates an open pathway for fungal pathogens to enter the neck. Allow the plant to initiate its own shutdown sequence on a stretch of dry, sunny days.

Once the tops have fallen, the root system begins to die back and the outer skin layers start to dry. Withhold irrigation immediately to prevent root re-growth or bulb rot in the soil. Leaving mature bulbs in wet ground for even a few days too long significantly increases the risk of neck rot and sour skin during winter storage.

Digging Fork – DeWit 4-Tine Long Handle Spading Fork

Yanking mature onions straight out of the ground by their dried stems often damages the delicate neck tissue, compromising the bulb’s natural seal. A heavy-duty digging fork is essential for sliding underneath the root zone to loosen the soil bed before lifting. This allows the bulbs to be extracted effortlessly with root systems and necks completely intact.

The DeWit 4-Tine Long Handle Spading Fork stands out due to its hand-forged boron steel construction and solid European ash handle. Unlike cheap stamped-steel garden forks that bend under the torque of heavy, compacted garden soil, this single-piece forged head effortlessly handles rocky or clay-heavy beds.

• Tine Material: Hand-forged, heat-treated boron steel
• Handle: FSC-certified solid European ash wood
• Ideal Application: Deep bed loosening without bulb contact
• Maintenance: Wipe tines clean of soil and oil annually

Keep the tines roughly four to six inches away from the bulb base when driving the fork into the bed. Lever gently backward to crack the root-to-soil bond before lifting the bulb by hand. This tool is built to last a lifetime for market gardeners and homesteaders, though urban gardeners in strictly loose raised beds might find it heavier than necessary.

Harvest Snips – ARS 300L Curved Pruning Shears

Once onions have completed their curing phase, the dried tops and trailing roots must be neatly trimmed before the crop is packed away. Standard garden loppers or kitchen scissors crush the hollow dried stems and tear away valuable outer skin layers. Specialized harvest snips offer the surgical precision needed to clean hundreds of bulbs quickly without nicking the shoulders.

The ARS 300L Curved Pruning Shears are the premier choice for harvest prep thanks to their rounded, curved blade tips. This subtle curve allows the blade to glide flush over the contours of the bulb shoulder, trimming stems down to one inch without risk of puncturing the cured papery skin.

• Blade Construction: High-carbon, hard-chrome plated steel
• Blade Shape: Curved blunt-nose profile to prevent bulb punctures
• Spring Action: Smooth internal coil spring for high-volume snipping
• Best Used For: Trimming roots to 1/2 inch and neck stems to 1 inch

These shears require periodic wiping with rubbing alcohol to remove sticky dried sap, but their edge retention is unmatched in high-volume processing. For growers curing softneck onions intended exclusively for braiding, these snips are unnecessary, but for crate or bag storage, they are indispensable.

Field Crate – Orbis Stacking Vented Harvest Lug

Moving several hundred pounds of freshly lifted onions from garden beds to curing spaces requires containers that offer structural rigidity and immediate airflow. Tossing bulbs into solid buckets or plastic totes traps ground moisture and heat, accelerating fungal development. Heavy-duty vented lugs keep bulbs organized and breathing from the moment they leave the dirt.

The Orbis Stacking Vented Harvest Lug provides the ideal balance of rugged durability and maximum ventilation. Constructed from heavy-duty, food-grade high-density polyethylene, these crates feature slotted walls and bottoms that allow continuous horizontal and vertical air circulation while blocking dirt accumulation.

• Material: High-density food-grade polyethylene (HDPE)
• Ventilation: Fully slotted sides and bottom for 360-degree airflow
• Handling: Integrated side hand-grips for balanced carrying
• Stacking: Interlocking tabs for safe vertical staging

Because they stack securely when full, these lugs let small-scale growers consolidate massive harvests into compact vertical footprints without crushing the bottom layers. Avoid stacking more than five crates high to maintain structural stability, and rinse them with a hose between harvests to eliminate lingering soil-borne spores.

Essential Steps for Preliminary Field Curing Outdoors

Preliminary field curing begins the process of transforming raw garden produce into bulletproof storage staples. If dry, sunny weather is forecast for several days post-harvest, lay the pulled onions directly on the soil surface or over clean landscape fabric. Arrange the plants in shingled rows, using the leafy foliage of one row to cover the exposed bulbs of the previous row.

This "shingling" technique shields tender onion shoulders from intense ultraviolet light, preventing sunscald which turns outer flesh soft and watery. Allow the roots and outer wrappers to lose moisture under full sun for two to three days. During this window, the green foliage rapidly draws down remaining moisture, concentrating sugars within the bulb.

Keep a close eye on ambient humidity levels and sudden weather shifts during field curing. If morning dew is heavy, wait until the sun completely dries the crop before handling or moving the bulbs. If rain threatens at any point during this preliminary window, immediately transfer the crop to a covered, well-ventilated outbuilding.

Drying Rack – Hydrofarm Hanging Mesh Plant Dryer

When outdoor weather turns wet or garden space must be cleared quickly, curing must transition indoors to an outbuilding, shed, or garage. Laying hundreds of onions out flat across tables rapidly consumes valuable floor space. A multi-tier hanging rack leverages vertical ceiling height while exposing every single bulb to uninterrupted airflow.

The Hydrofarm Hanging Mesh Plant Dryer solves indoor space limitations with its multi-tiered, breathable nylon design. The heavy-duty micro-mesh shelving allows air to pass freely through the underside of the bulbs, eliminating the need to manually flip each onion daily during the drying cycle.

• Design: Collapsible multi-tier suspended drying chamber
• Fabric: High-durability breathable nylon mesh with wire framing
• Attachment: Heavy-duty Velcro top strap for rafters or ceiling hooks
• Storage: Folds completely flat into an included zippered pouch

Distribute bulbs evenly across each tier in a single layer to avoid crowding, which can create pockets of dead air. While ideal for small-to-midscale home harvests up to 100 pounds, large commercial scale crops will require built-in wooden lath shelving due to weight restrictions.

Circulation Fan – Vornado 630 Mid-Size Air Circulator

Natural ambient airflow inside a closed garage, barn, or basement is rarely sufficient to pull thick moisture out of onion necks before mold takes hold. Standard oscillating fans simply sweep a narrow beam of air back and forth across the room, leaving large dead zones. Continuous whole-room air circulation is non-negotiable during the first two weeks of indoor curing.

The Vornado 630 Mid-Size Air Circulator utilizes specialized vortex aerodynamics to continuously move all the air within a curing space rather than just blowing across a localized target. Its deep-pitched blades and enclosed duct system push air up to 70 feet, keeping the environment around every drying rack active and turbulent.

• Air Movement: Whole-room vortex circulation up to 70 feet
• Speed Settings: 3-speed mechanical control switch
• Adjustability: Multi-directional pivoting head for targeted deflection
• Maintenance: Removable front grill for seasonal dust cleaning

Aim the fan at an adjacent wall or ceiling rather than pointing it directly at the drying racks. This creates a gentle, continuous room-wide swirl that lifts moisture away from damp necks without desensitizing the bulb wrappers. Run the unit continuously on medium speed throughout the active curing period.

Digital Hygrometer – ThermoPro TP50 Climate Monitor

Guessing temperature and humidity levels during curing is a common mistake that often leads to ruined harvests. Onions release gallons of water vapor into the air during the first ten days of drying, causing indoor relative humidity to spike silently. A responsive digital monitor provides real-time data so ventilation adjustments can be made proactively.

The ThermoPro TP50 Climate Monitor is a reliable, high-precision gauge designed to track ambient moisture and temperature fluctuations continuously. Featuring a clear, easy-to-read LCD screen, it records 24-hour high and low metrics, allowing growers to catch dangerous overnight humidity spikes that occur when outdoor temperatures fall.

• Update Frequency: Measures conditions every 10 seconds
• Humidity Accuracy: Precise within ±2 to 3% relative humidity
• Mounting: Tabletop kickstand, magnetic back, and wall mount
• Display: Instant comfort level indicator with min/max tracking

Place the unit directly at shelf level alongside the curing bulbs rather than near windows or doors. If relative humidity pushes above 70 percent during curing, immediately crack a window, vent the room, or turn on a dehumidifier to keep the drying process moving forward.

Mesh Bags – Johnny’s Selected Seeds Red Mesh Sacks

After necks are trimmed and outer wrappers are rustling dry, onions need a storage medium that prevents moisture pockets while maintaining structural support. Packing cured bulbs into cardboard boxes or plastic tubs invites stagnant humidity and premature sprouting. Heavy-duty mesh sacks allow the crop to stay cool and aerated in bulk.

The Johnny’s Selected Seeds Red Mesh Sacks are the industry standard for small-scale winter root and bulb preservation. Manufactured from woven open-mesh polypropylene, these durable sacks allow total light penetration checkups and maximum ventilation while easily holding up to 50 pounds of dense produce.

• Material: UV-treated, woven polypropylene mesh
• Closure: Heavy-duty integrated woven drawstring
• Capacity Options: Available in 25 lb and 50 lb configurations
• Durability: Fully reusable across multiple seasons without unraveling

Hang filled sacks from rafters or secure wall hooks to keep the bulbs completely elevated above cool, damp basement floors and out of reach of rodents. Avoid stuffing bags beyond their capacity, as overfilled bags compress the center bulbs and restrict internal airflow.

Braiding Twine – Nutscene Heritage Spool Jute String

Softneck and long-stemmed storage onions can be braided together into traditional hanging clusters, offering a decorative and highly functional alternative to mesh sacks. Braiding keeps each individual bulb visible for easy inspection throughout the winter while saving precious shelf space. Strong, natural twine is necessary to reinforce the structural spine of the braid.

The Nutscene Heritage Spool Jute String provides the ideal blend of tensile strength, natural friction, and biodegradability. Spun in the United Kingdom using traditional three-ply construction, this jute twine grips dry, slick onion foliage tightly without slipping, preventing heavy lower bulbs from breaking free under load.

• Composition: 100% natural, three-ply biodegradable jute
• Tensile Strength: High-friction grip suited for vertical load bearing
• Core: Tangle-free center-pull spool design
• Best Used For: Softneck braids and tied curing bunches

Cut three equal four-foot lengths of jute and tie them together at the top to form the core of your braid. Incorporate onion stems alongside the jute strands as you weave down, pulling each knot snug against the neck. This technique takes some practice to master, but results in secure strings that can hang for months in a cool pantry.

Managing Proper Temperature and Moisture Levels

Successfully transitioning onions from active curing to dormant winter storage requires a two-stage environmental strategy. The curing phase demands temperatures between 75°F and 85°F alongside low relative humidity (below 65%) to rapidly seal outer wrappers and dry out the vascular bundles within the neck. High airflow is paramount during this stage to drive off expelled moisture.

Once the necks are tightly sealed and roots are completely brittle, the bulbs must be moved into long-term dormant storage. The ideal winter holding environment is cold, dry, and dark, with target temperatures between 32°F and 40°F and relative humidity holding steady between 60% and 65%. Temperatures above 50°F will trigger dormant bulbs to break dormancy and send out green shoots.

Avoid storing onions alongside apples, pears, or potatoes. Apples and ripening tree fruits emit ethylene gas, which triggers rapid sprouting in cured alliums. Potatoes continuously release high amounts of moisture, which softens cured onion skins and invites rot.

Inspecting and Storing Cured Bulbs for the Winter

Before packing onions away for the cold season, inspect every single bulb individually with a critical eye. A properly cured onion should feature an entirely dry, straw-like neck with no green tissue remaining inside the core. Squeeze the neck firmly just above the bulb shoulder; any spongy or soft texture indicates incomplete curing or internal decay.

Set aside any "thick-necked" onions or bulbs that show signs of mechanical damage, soft spots, or mildew. These specimens should not be placed into long-term bulk storage, as a single rotting bulb can spread decay to adjacent clean onions. Eat these imperfect culls first, as they remain perfectly delicious for fresh cooking over the coming weeks.

Maintain a regular inspection routine throughout the winter months by checking hung mesh bags every few weeks. Feel the lower sections of the bags for softening bulbs and remove suspect globes immediately. With well-cured stock and diligent storage monitoring, firm, sweet home-grown onions will reliably last until the following spring’s planting begins.

Curing storage onions is a straightforward post-harvest craft that turns a seasonal garden surplus into months of kitchen resilience. Equipping the workflow with the right digging, drying, and storage gear preserves all the labor invested in the growing season. Take the time to dry them thoroughly, store them cool, and enjoy garden-fresh flavor all winter long.