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When to Plant Garlic in Washington County, RI

Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.

Washington County, Rhode Island is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 21, giving you a growing season of approximately 181 days.

At an elevation of 519 feet, Washington County receives approximately 41.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Garlic during the growing season.

Washington County, RI (Zone 6b) Moderate season
181 days
Last Spring Frost April 23
181 growing days
First Fall Frost October 21

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 17 🍅 Harvest: Jul 17 – Oct 30
Recommended (50%) ✗ May not fit
Transplant: Apr 23 🍅 Harvest: Jul 23 – Nov 5
Safe Start (90%) ✗ May not fit
Transplant: May 14 🍅 Harvest: Aug 13 – Nov 26

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 52 gal / 100 sq ft
Garlic needs ~2,269 GDD — county provides 2,488 GDD Good fit

Garlic Planting Timeline โ€” Washington County, RI

Garlic Planting Calendar

Activity When Date Range
Fall Sowing September 9 Sep 9 โ€“ Sep 23

Plant 1" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June โ€”
July โ€”
August โ€”
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“240 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

181 days

Growing Tips for Washington County

Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Level Up Your Garden

Frequently Asked Questions

When should I plant Garlic in Washington County, RI?

Washington County is in Zone 6b with an average last frost of April 23. Plan your Garlic planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, RI?

Washington County, Rhode Island is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Washington County, RI. Local conditions may vary. Last updated: April 2026.