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When to Plant Sunchoke in Lincoln County, OR

Lincoln County, Oregon Zone 9a May

Your May game plan for Lincoln County, Oregon

We've pulled the most time-sensitive tasks for Lincoln County, Oregon this May and put them front and centre. Tackle them in order.

Avg. last frost April 19
Avg. first frost October 31
Soil temp (4") 69°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Plant out sunchoke

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

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Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

Lincoln County, Oregon is in USDA Zone 9a. The average last spring frost is April 19 and the first fall frost is October 31, giving you a growing season of approximately 195 days.

At an elevation of 267 feet, Lincoln County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Sunchoke to ensure they mature before fall.

Lincoln County, OR (Zone 9a) Moderate season
195 days
Last Spring Frost April 19
195 growing days
First Fall Frost October 31
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Lincoln County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Transplant: Apr 18 🍅 Harvest: Aug 8 – Oct 3
Recommended (50%) ✓ Fits season (13 days to spare)
Transplant: May 3 🍅 Harvest: Aug 23 – Oct 18
Safe Start (90%) ✓ Fits season (23 days to spare)
Transplant: May 25 🍅 Harvest: Sep 14 – Nov 9

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.

Soil Compatibility in Lincoln County

How your county's soil matches Sunchoke's growing requirements.

Soil pH

Your soil pH (5.5–6.4) is more acidic than Sunchoke prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Lincoln County is excellent for Sunchoke — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.9%) — Sunchoke will thrive.

How to Plant Sunchoke

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 192 gal / 100 sq ft

Monthly Watering Guide for Sunchoke

Sunchoke needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunchoke Needs Rainfall You Supplement Action
Jan 6.1" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.7" 3.6" 🚿 Regular watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 6.3" 0" ❄️ Dormant
Dec 5.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Lincoln County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sunchoke Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Sunchoke needs ~1,592 GDD — county provides 2,388 GDD Excellent fit

Sunchoke Planting Timeline — Lincoln County, OR

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 3 May 3 – May 17
Harvest August 23 Aug 23 – Oct 18

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
August Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

195 days in Lincoln County

Growing Tips for Sunchoke in Lincoln County

Direct sow Sunchoke outdoors after April 19 in Lincoln County when soil has warmed and frost danger has passed.

Common pests for Sunchoke in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunchoke in Lincoln County, OR?

Lincoln County is in Zone 9a with an average last frost of April 19. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lincoln County, OR?

Lincoln County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 19 and first fall frost is October 31.

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Your Lincoln County Garden Planner — Free

A 24-page printable planner built for Lincoln County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Lincoln County, OR. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.