When to Plant Garlic in Pennsylvania: A Complete Growing Guide

Pennsylvania is one of the best garlic-growing states in the Northeast — rich soils, cold winters, and a long agricultural tradition make it prime territory for hardneck varieties in particular. From the Allegheny Plateau to the Lancaster County farmlands to the Pocono highlands, Pennsylvania gardeners can grow exceptional garlic. There's just one pest worth knowing about: the Allium Leafminer, an invasive fly that has spread across much of the state and requires a simple but important timing adjustment to avoid.

Pennsylvania's Garlic Growing Zones

• Northwestern Pennsylvania (Erie, Meadville): Zones 5b–6a. Cold winters with lake-effect snow — hardneck varieties thrive here.
• Northcentral and Northeast Pennsylvania (Williamsport, Scranton, Pocono Mountains): Zones 5b–6b. Cold winters — excellent hardneck territory.
• Western Pennsylvania (Pittsburgh, Uniontown): Zones 6a–6b. Moderate winters — hardneck and softneck varieties both perform well.
• Central Pennsylvania (State College, Harrisburg, Altoona): Zones 6a–6b. Moderate winters — excellent conditions for hardneck and softneck varieties.
• Southeast Pennsylvania (Philadelphia, Lancaster, Chester County): Zones 6b–7a. Milder winters — hardneck and softneck varieties both perform well, with softnecks especially reliable.

When to Plant Garlic in Pennsylvania — and Why Timing Matters

Pennsylvania gardeners have an extra reason to pay close attention to planting timing: the Allium Leafminer (Phytomyza gymnostoma), an invasive fly that has spread across much of the state since its arrival in 2015. The adult fly is active in two windows — March through May and September through November — and lays eggs in garlic and other allium foliage. The larvae tunnel through leaves and stems, causing significant damage.

The good news: planting later in the fall — after the fly's fall activity window closes — is one of the most effective ways to protect your crop. Penn State Extension recommends planting after the first hard frost (below 28°F) to minimize leafminer exposure. Read Penn State Extension's full guidance on planting late to avoid Allium Leafminer →

• Northwestern PA (zones 5b–6a): After first hard frost, typically late October to early November
• Northcentral and Northeast PA (zones 5b–6b): After first hard frost, typically late October to early November
• Western and Central PA (zones 6a–6b): After first hard frost, typically late October to mid-November
• Southeast PA (zones 6b–7a): After first hard frost, typically early to mid-November

Plant when soil temperatures drop to 50–60°F and after a hard frost has knocked back the leafminer population. Garlic planted later still establishes roots before the ground freezes and overwinters successfully — don't be afraid to plant into November across most of Pennsylvania.

The Best Garlic for Pennsylvania

Pennsylvania's cold winters make it outstanding hardneck territory statewide. Softnecks are a reliable option as well, particularly in Southeast Pennsylvania.

Hardneck Varieties (Excellent Statewide, zones 3–8)

• German Red — Rocambole hardneck, zones 3–8, widely regarded as one of the best-tasting hardneck varieties available. Rich, complex, and deeply savory — a classic that thrives in Pennsylvania's cold winters.
• Russian Red — Marbled Purple Stripe hardneck, zones 3–8, rich and full-flavored with beautiful deep purple marbling. One of the most cold-hardy varieties we carry.
• Chesnok Red — Purple Stripe hardneck, zones 3–8, prized by chefs for its exceptional roasting qualities.
• Music — Porcelain hardneck, zones 3–8, large beautiful bulbs with bright white wrappers and a bold, rich flavor. A perennial favorite with Pennsylvania gardeners.
• Persian Star — Asiatic hardneck, zones 3–8, stunning purple-striped wrappers and rich, complex flavor.

Softneck Varieties (Reliable Statewide, especially Southeast PA)

• Inchelium Red — Artichoke softneck, zones 5–10, taste-test champion with very large bulbs.
• Messidor — French white artichoke softneck, mild and balanced flavor, large uniform bulbs.
• Castano — Artichoke softneck, rich and savory flavor, reliable producer.

How to Plant Garlic in Pennsylvania

1. Prepare your bed: Pennsylvania soils range from the incredibly fertile limestone soils of Lancaster County and the Cumberland Valley to the rocky, acidic soils of the Pocono and Allegheny highlands. All benefit from generous compost additions. Acidic highland soils may benefit from a lime application to raise pH toward the ideal 6.0–7.0 range.
2. Break your bulbs: Separate cloves just before planting. The largest cloves produce the largest bulbs.
3. Plant depth and spacing: 2 inches deep, pointed end up, 6 inches apart in rows 12 inches apart.
4. Mulch well: A 4–6 inch layer of straw mulch after planting protects roots through winter and moderates soil temperature.
5. Spring care: Remove mulch gradually as temperatures warm in March. Apply a nitrogen-rich fertilizer when you see green growth. Stop fertilizing by mid-April. Watch for leafminer activity in spring (March–May) — row covers can help protect plants during this window.

Managing Allium Leafminer in Pennsylvania

• Two activity windows: Adult flies are active March–May and September–November. Eggs are laid in foliage; larvae tunnel through leaves and stems.
• Best prevention — plant late: Planting after the first hard frost (late October to November) dramatically reduces exposure.
• Row covers: Floating row covers applied in early March and removed after the spring flight (late May) protect plants from spring damage.
• Crop rotation: Avoid planting alliums in the same bed year after year.
• More info: Read our full Allium Leafminer guide →

When to Harvest Garlic in Pennsylvania

• Southeast Pennsylvania (zones 6b–7a): Late June to early July
• Western and Central Pennsylvania (zones 6a–6b): Late June to early July
• Northwestern, Northcentral, and Northeast Pennsylvania (zones 5b–6b): Early to mid-July

Harvest when about half the leaves have browned and half are still green.

💡 Pro tip: Always dig a test bulb first! Before pulling your entire crop, dig one bulb and inspect it. The cloves should be plump and well-formed, filling out the wrapper. If they look small or the skin is very tight, give it another week.

Curing and Storing Pennsylvania Garlic

Pennsylvania's summer humidity makes curing conditions tricky. Move harvested garlic immediately to a well-ventilated, shaded space with excellent airflow. Cure for 3–4 weeks before trimming and storing. Hardneck varieties store 4–6 months; softneck varieties store 9–12 months.

Ready to Grow Pennsylvania Garlic?

Our seed begins shipping in September — giving you plenty of time to plan your late-fall planting and beat the leafminer. Whether you're gardening in Lancaster County or the Pocono highlands, we have the right variety for your zone.

• Shop Hardneck Seed Garlic → — German Red, Russian Red, Chesnok Red, Music, and Persian Star for Pennsylvania's cold winters
• Shop Softneck Seed Garlic → — Inchelium Red, Messidor, and Castano — reliable choices statewide