When to Harvest Garlic: Expert Tips for Perfect Timing

Understanding how to harvest garlic will ultimately affect the quality of your bulbs. Garlic develops through specific stages from its planting until it is ready for harvesting. The green shoots emerge in early spring, followed by leaves. After the garlic has experienced the longest day of the year, it begins forming bulbs.

Harvest timing is indeed more related to your climate zone than the calendar. In cooler climate zones such as 3-5, garlic is typically ready for harvest from mid-July until August. In warmer climate zones such as 6-8, it is often ready by late June. It is important to look at the plants, rather than the calendar. Soil type may also affect this timing.

Bulbs in heavy clay soils develop more slowly than in more sandy soils. I remember losing a crop one year because I harvested too early in heavy, dense soil. To test for bulb size, brush all the dirt off of one plant. If the cloves fill the wrappers and there is no gap, it's ready to be harvested.

The timing of harvest affects storage longevity. Garlic harvested early will lack protective wrappers and will spoil quickly. Garlic harvested too late could lead to split bulbs with the cloves exposed. The goal is to have the lower 50% of the leaves yellow. The upper leaves should still be green and look vigorous.

Hardneck garlic, as well as softneck or artichoke varieties, exhibit different signals of readiness for harvest. The hardneck varieties create a clear decision, letting you know when to harvest when there are still 4-5 green leaves lying above ground. Softneck varieties require you to get up close and personal with the bulbs since you want to harvest when they have 1-2 green leaves remaining. All cover the bulb in papery wrappers, but the firmness of the neck indicates the bulb is ready for harvest.

Look at the soil line on the wrappers for evidence of harvest. Hardneck wrappers cling more tightly to the bulb, while softneck wrappers separate more easily. Rubbing the wrapper between your fingers will give you a sense of the moisture level. If the wrapper feels crisp and crackles like parchment, your garlic is likely ready to dig. I've miscalculated this many times before losing whole bulbs to rot.

The timing of scape removal directly impacts harvest windows for hard necks. Once curly scapes have been cut away, anticipate approximately 3 weeks for the bulbs to reach full maturity. This waiting period allows the bulbs to expend energy diverted into cloves. So, make sure to note when you harvest scapes and then monitor the actual harvest date. Softnecks do not have scapes, but should still be monitored by leaf-count. Leaf count should yield similar accuracy in judging harvest time.

Once the lower leaves start to yellow, compare bulb sizes every week. Mature hard necks will push up against the soil and show splits in the bulbs. Softnecks may stay below the soil line, making leaf counts important. I made the mistake last season of harvesting a soft neck patch too early. The wrappers fell apart during the cure and after months of growth, I lost all of my progress.

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Leaf yellowing pattern

• Lower leaves yellow first while upper leaves maintain green coloration
• Optimal harvest occurs when 50-60% of lower foliage shows discoloration
• Premature yellowing across all leaves suggests nutrient deficiency or disease
• Weekly monitoring recommended during last month of growth cycle
• Compare leaf color to standardized yellowing progression charts
• Discoloration should progress upward from oldest to newest leaves

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Bulb wrapper integrity

• Gently remove surface soil to inspect wrappers without damaging them
• Mature bulbs show 3-4 intact papery layers above soil level
• Wrappers should crinkle audibly when rubbed between fingers
• Avoid bulbs with visible splits or fungal spotting on wrappers
• Ideal wrapper color ranges from ivory white to light tan
• Thicker wrappers indicate better storage potential post-harvest

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Stem rigidity test

• Apply gentle pressure to stem 2 inches above soil line
• Mature hardneck stems resist bending without snapping
• Softneck stems remain flexible but show reduced elasticity
• Test multiple plants to account for individual growth variations
• Combine with leaf count assessment for accuracy
• Overly rigid stems may indicate delayed harvesting window

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Post-scape timeline

• Begin daily monitoring 21 days after scape removal
• Bulb size increases rapidly during final 3-week period
• Harvest window opens when 30% of wrapper layers dry
• Delayed harvesting beyond 28 days risks bulb separation
• Track scape removal dates using gardening journal or app
• Combine with soil moisture tests for optimal timing

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Bulb shoulder development

• Inspect bulb shoulders through soil using dental mirror
• Mature bulbs show rounded shoulders without neck constriction
• Undersized bulbs appear tapered at the stem connection
• Compare to variety-specific shoulder shape references
• Measure bulb diameter against expected size charts
• Should account for 75% of expected mature size

Assess soil moisture levels 48 hours before harvesting. The optimal moisture level is when the soil feels like a wrung-out sponge; it should not be wet and soggy but simply moist. A finger test works well; dig down a couple of inches, and if the soil clumps together (but does not drip), you are ready to go. If the soil is too dry, it will crack the bulbs when extracting them. I learned this the hard way after losing a crop because of extremely hard ground due to drought.

At a 45-degree angle, position your garden fork 6 inches from the base of the plants. Stick it straight down into the soil and rock it back to lift the bulbs without breaking them. Do not ever pull the stems, as that will remove the cloves from the basal plates. Use a garden claw for clay soil instead of a garden fork. To guarantee the integrity of the wrappers, angle the garden tool the right way.

Moist soil requires coddling. Rather than shaking bulbs, simply brush off the mud. Let bulbs dry in an upright position for 12 hours before curing. For dry soil, dust soil off the bulb immediately with a soft brush. Following last fall's rain-soaked harvest, I now always favor drying racks for drying bulbs instead of curing them in the field.

After harvesting, disinfect all tools with a 10% bleach solution. Clear all root fragments and leaf debris from the wooden beds. Rotate crops to break pest cycles. I spread aged compost immediately after clearing fields. This process rebuilds the soil structure before fall, allowing time for cover crops to establish.

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Pre-Harvest Soil Prep

• Cease irrigation 7 days before planned harvest date using calendar alerts
• Verify soil moisture at 4-inch (10 cm) depth using manual probe or digital meter
• Create loose perimeter around bulbs with hand trowel to ease lifting
• Remove surface mulch 24 hours prior for natural soil compaction
• Avoid nitrogen-rich fertilizers 3 weeks before harvest timeline
• Mark harvest-ready plants with colored tags for easy identification

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Bulb Extraction Technique

• Position spading fork at 45° angle 6 inches (15 cm) from plant base
• Leverage body weight to lift soil mass without yanking stems
• Shake bulbs gently while supporting stem base with opposite hand
• Inspect for damage: discard bulbs with pierced wrappers immediately
• Maintain 2-inch (5 cm) stem length during initial field processing
• Place undamaged bulbs in wide, shallow containers for transport

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Field Curing Setup

• Select shaded area with 60-70% humidity for initial drying
• Arrange bulbs in single layer on elevated mesh racks
• Rotate bulbs 180° daily to ensure even airflow exposure
• Monitor morning dew accumulation using moisture sensor strips
• Implement rodent deterrents around curing area perimeter
• Cover with breathable row cover during unexpected rainfall

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Post-Harvest Cleaning

• Use soft-bristled brush to remove remaining soil particles
• Avoid washing bulbs with water to prevent mold growth
• Inspect wrapper layers under bright natural light for defects
• Trim roots to ¼ inch (0.6 cm) using sterilized pruning shears
• Group bulbs by size for uniform curing timelines
• Temporary storage in ventilated crates before curing

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Curing Environment Monitoring

• Maintain 65-75°F (18-24°C) temperature during first curing week
• Ensure continuous airflow with oscillating fans at low speed
• Measure humidity levels twice daily using digital hygrometer
• Adjust ventilation based on wrapper drying progression rates
• Check for condensation buildup under racks every 12 hours
• Record environmental data in harvest logbook for quality control

While curing, hard necks need to be stored at humidity levels between 45 and 55%. In comparison, soft neck varieties need to be stored between 60 and 65%, with minimal adverse effects. I once stored hard necks in conditions with 70% humidity and saw sprouting within a couple of weeks. Use a hygrometer. Porcelain types need less moisture to avoid wrapper decay, while silverskins respond more favorably to elevated moisture levels.

Using sharp scissors, trim cleaned and dried stems a minimum of 1.5 inches above the bulbs. Make your cut at a 45-degree angle so moisture can't pool at the intersection of the bulb and stem. If braiding, leave the stems a minimum of 8 inches but allow them to dry completely. Never make a cut flush to the bulb, as it will lead to rot.

When it comes to curing spaces, creating airflow is more important than temperature. Set fans up to provide a cross-breeze that doesn't blow the fan directly on the bulbs. Open mesh racks trump solid shelves, they allow 360º circulation. I rigged up a used greenhouse with louvered vents to accomplish this. Stagnation spreads mold faster than heat will.

Combat humidity spikes by hanging calcium chloride packets near your bulbs. When the weather is rainy, space your garlic 3 inches apart on the racks. If you see any white hairy mold in the crop, separate that bulb from the rest and wipe it with a cloth dampened in vinegar if the mold is light enough. Last monsoon season, that kept 90% of what would otherwise be rotten, out of ruin!

Softneck garlic varieties can be stored for a period of 10-12 months in ideal conditions; hardneck varieties last 4-6 months. I once lost a Rocambole crop because I thought they would store like Silverskins. You should be sure to track different varieties of garlic separately. Porcelain varieties come in between 6-8 months if you can control humidity precisely.

At 60-70°F, softnecks require a humidification level of 60-65 percent. Hardnecks perform well at 50-60°F and 50-55 percent humidity. A hygrometer is a useful way to measure humidity, and my $12 model has saved all my bulbs from rotting. Bulbs should be kept in the dark. Light will start to sprout bulbs even in the greatest conditions.

It is necessary to air out mesh bags every week. The slats of wooden crates must have 2-inch outlets in between the slats. I have run small batches in ceramic jars that have cork lids. Just wipe the inside with vinegar monthly. I used cardboard boxes multiple times last winter and because of condensation ruining 30 bulbs the last time, this is a waste of boxes for testing.

To avoid condensation, put silica gel packets underneath container lids. In humid locations, clean containers with cedar shavings. Rotate the bulbs from time to time to capture both sides. Last July, when I saw droplets in my root cellar, cloth sacks with rice in them saved my harvest.

Small bulb clusters can be caused by poor soil fertility or overcrowding. An example from too much crowding I planted garlic cloves only 2 inches apart and had a spectacular harvest of marble-sized bulbs. To give garlic the best chance for a full-sized bulb, always plant cloves at least 6 inches apart in amended nutrient-rich soil, such as compost. Additionally, inconsistent watering during the bulbization stretch of growth will reduce bulb size potentially forever.

If you see yellowing leaves early in the season, your plants might have a fungal disease, or nematodes may be affecting your plants. Inspect the roots for lesions, a sign of onion maggots. Last year I lost 20 plants to Fusarium. Treat the soil with biofungicides before you plant. Make sure it drains properly to avoid waterlogged conditions that can cause yellowing.

Bulb splitting happens when you wait too long to harvest and the moisture in the soil fluctuates. After the green leaves have faded down to 5-6, it is time to harvest. Be sure to use a garden fork, and turn it at an angle away from the stems, as this prevents mechanical damage. I only learned this lesson after splitting off 30% of my crop by simply tugging on the stems.

To combat mold, space bulbs are at least 4 inches apart on drying racks in a well-ventilated place. In the extremely humid conditions of the monsoon season, I will also use box fans set to low speed in proximity to curing garlic. If white mold appears, wipe your bulbs down with cloths dampened with vinegar, which some claim will eradicate the spores. When ready, store cured garlic, along with silica gel packets, in breathable containers.

Learning when to harvest garlic requires experience and observing both the color of the leaves and the wrapping of the bulb. I remember harvesting early and having shriveled garlic. Allowing some leaves to turn yellow, 40 to 50%, works to retain intact wrappers. This visual indicator is universal across climates and soil types.

Cure garlic at 60-70°F with airflow for 3 weeks then store hardnecks at 32-40°F. Softnecks tolerate 50-60°F but need 60-70% humidity. I keep a thermostat in the basement, and this inexpensive, $15 thermometer tool will help you avoid storage disasters. You will need to keep an eye on it every week, so watch the thermometer. Depending on the season, you should adjust containers.

A hardneck garlic will deteriorate and require different techniques to work with when you intend to use it within 6 months. Softnecks stored correctly can last around 10-12 months. This past year, I stored a variety of Spanish Roja hardneck garlic alongside the silverskins. By February, the hardneck garlic had sprouted, while the softnecks were still firm and intact. I've learned to mark what I have and when I stored it!

To prevent pests, rotate crops every year and wash out containers with vinegar. I put diatomaceous earth around my curing racks following a mite infestation. I routinely look over my garlic bulbs every week for soft spots. If garlic is affected, isolating the impacted heads is a more effective way to preserve your crop than prior treatments or any kind of reactive treatment.