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When to Plant Angelica in Benton County, OR

Angelica is a dramatic biennial herb that can reach 6 feet tall with large compound leaves and globe-shaped flower clusters. All parts are edible with a sweet, celery-like flavor.

Benton County, Oregon is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.

At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Angelica during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Angelica root diseases.

Benton County, OR (Zone 8a) Moderate season
199 days
Last Spring Frost April 14
199 growing days
First Fall Frost October 30

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Start indoors: Feb 20 Transplant: Mar 20
Recommended (50%) ✓ Fits season
Start indoors: Mar 10 Transplant: Apr 7
Safe Start (90%) ✓ Fits season
Start indoors: Apr 2 Transplant: Apr 30

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
1.5″/week
Rainfall provides
1.1″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 672 gal / 100 sq ft
Angelica needs ~7,528 GDD — county provides 2,736 GDD May not mature

Angelica Planting Timeline โ€” Benton County, OR

Angelica Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 7 Apr 7 โ€“ Apr 21
Direct Sow March 31 Mar 31 โ€“ Apr 21
Fall Sowing August 21 Aug 21 โ€“ Sep 4

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
July โ€”
August Fall Sowing
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

365โ€“730 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 8a

Growing Season

199 days

Growing Tips for Benton County

Sow fresh seeds in fall for spring germination. Provide rich, moist soil and partial shade. Harvest stems in the second year before flowering for candying or flavoring.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Angelica in Benton County, OR?

Benton County is in Zone 8a with an average last frost of April 14. Plan your Angelica planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Benton County, OR?

Benton County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Benton County gardeners in Zone 8a 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 Benton County, OR. Local conditions may vary. Last updated: April 2026.