How to grow garlic: a commercial guide

Choose the type and clean seed

Hardneck or softneck

Hardneck types overwinter better in the Midwest, have stronger flavour and peel more easily, and produce scapes. Softneck types keep longer and have milder flavour and smaller cloves. Elephant garlic is grown like garlic but is milder.¹

Start from healthy seed

White rot, botrytis leaf blight, downy mildew and Fusarium basal rot are the documented threats. Rutgers recommends clean planting stock and a robust crop rotation; discard cloves with blemishes or disease.^3,2

Seed quantity

Oregon State gives 1,790–2,240 kg/ha (1,600–2,000 lb/acre) of California Early cloves, or 1,570–1,910 kg/ha (1,400–1,700 lb/acre) of California Late; elephant garlic needs 560–1,120 kg/ha (500–1,000 lb/acre).⁴

Plant in the fall

Date

The Midwest guide says plant 6–8 weeks before the ground freezes so roots form but shoots do not emerge; Rutgers says no later than 3–4 weeks before the first anticipated killing frost; Oregon plants in September or early October.^1,3,4

Depth depends on winter

Depths range from 2.5–10 cm (1–4 inches) across these sources. The deeper figure is for colder Midwest winters with mulch; check your local extension recommendation.^1,2

Orientation

For mechanical cultivation plant the flat side of the clove perpendicular to the row; for hand cultivation in dense plantings plant it parallel.¹

Fertility and water

Soil pH

Maintain pH 6.0–6.8 on mineral soils (Midwest guide); Penn State gives 6.0–6.5.^1,2

Nitrogen programme

Midwest guide: about 28 kg N/ha (25 lb N/acre) before planting, then sidedress 22–45 kg/ha (20–40 lb/acre) N every 3 weeks, finishing 4–6 weeks before harvest, for a total of 80–140 kg N/ha (70–125 lb N/acre). Penn State suggests 140 kg/ha (125 lb/acre) split 75 / 25 / 25. Oregon uses 56–85 kg/ha (50–75 lb/acre) N in fall and 110–195 kg/ha (100–175 lb/acre) in spring.^1,2,4

Phosphorus and potassium

By soil test: up to 170 kg/ha (150 lb/acre) P2O5 and up to 110 kg K2O/ha (100 lb K2O per acre) (Midwest); Penn State suggests 170 kg/ha (150 lb/acre) of each.^1,2

Irrigation

About 2.5 cm (1 inch) of water per week in dry periods through mid-June, then stop to encourage maturation (Penn State).²

Manage scapes, rotation and disease

Remove scapes

Remove flower stalks as soon as they are visible for maximum bulb size. Scapes can be sold.^1,2,3

Rotation

Rotate away from alliums for 3–4 years: 4 years for Fusarium basal rot, 3 years for botrytis neck rot.¹

Insects

Onion maggot and onion thrips affect garlic too. Plant after the first-generation maggot flight (about 700 growing degree days, base 4°C (40°F)); the thrips threshold for several products is 1 thrips per leaf.¹

Harvest, cure and store

When to lift

Harvest when the tops have fallen over and partly dried, or when 40–60% of the leaves have yellowed (garlic has about six leaves). Mature bulbs come 70–110 days after spring regrowth.^1,2,3

Cure

Lift, then dry protected from sun and rain. Penn State cures about three weeks until outer leaves are completely dry; Rutgers gives 24–29°C (75–85°F) in a moisture-free place. Trim roots and tops after drying, or braid softneck.^1,2,3

Store

Oregon State stores commercial garlic at 0°C (32°F) and 65–70% relative humidity for 6–7 months; Penn State gives 0–2°C (32–35°F) and 65–75%; Rutgers describes cool, dry storage at 7–16°C (45–60°F). Store and ship below 15°C (59°F) and at low humidity to slow black mold.^4,2,3,1

Yield and economics

Yield varies widely by type, density and region. California, which grows nearly all US commercial garlic, averaged 15.7 t/ha (140 cwt per acre) in 2025 on 10,100 ha harvested (24,900 acres).

Price and cost benchmark

Rutgers puts retail commodity garlic at $1.50–2.50 per lb and production cost at about $1.00–1.25 per lb for small commercial growers. Garlic needs considerable labour for harvest and cleaning.³

Run your own numbers

Margin per hectare = saleable kg × price − (seed + labour + curing + storage). Use the crop ROI estimator with your own seed cost, which is a large share of the first year.⁵

Frequently asked questions

When should I plant garlic?

In fall: 6–8 weeks before the ground freezes in the Midwest, or 3–4 weeks before the first killing frost per Rutgers. Cloves root before winter and shoots emerge in spring.

How do you grow garlic from a clove?

Separate the bulb into cloves, plant each pointed end up 7.5–10 cm (3–4 inches) apart in rows, cover with soil and 5–10 cm (2–4 inches) of straw mulch, and leave through winter. Lift when the lower leaves have yellowed the next summer.

How deep and how far apart do you plant garlic?

Cloves 7.5–15 cm (3–6 inches) apart in rows 23–91 cm (9–36 inches) apart. Depth ranges from about 2.5–10 cm (1–4 inches) depending on region and source; deeper with mulch in cold winters.

How long does garlic take to grow?

Fall-planted garlic is harvested 70–110 days after it resumes growth in spring, so about 8–9 months from planting to lifting.

Should I cut garlic scapes?

Yes on hardneck garlic: removing the flower stalk as soon as it appears improves bulb size, and the scapes are edible.

How long does garlic keep?

Commercially cured garlic keeps 6–7 months at 0°C (32°F) and 65–70% humidity per Oregon State; softneck types generally store longer than hardneck.