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When to Plant Sunchoke in Benewah County, ID

Benewah County, Idaho Zone 6b May

May in Benewah County, Idaho — your action list

May is a pivotal month for Benewah County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 8
Avg. first frost October 1
Soil temp (4") 44°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Move sunchoke from tray to bed

    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.

Benewah County, Idaho is in USDA Zone 6b. The average last spring frost is May 8 and the first fall frost is October 1, giving you a growing season of approximately 146 days.

At an elevation of 6,081 feet, Benewah County receives approximately 20.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Sunchoke during the growing season.

Benewah County, ID (Zone 6b) Short season
146 days
Last Spring Frost May 8
146 growing days
First Fall Frost October 1
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Benewah County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 13 🍅 Harvest: Sep 2 – Oct 28
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Sep 11 – Nov 6
Safe Start (90%) ✗ May not fit
Transplant: Jun 20 🍅 Harvest: Oct 10 – Dec 5

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 Benewah County

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

Soil pH

Your soil pH (6.3–7.8) overlaps with Sunchoke's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Sunchoke.

How to Plant Sunchoke

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 626 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 2.5" 1.8" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Benewah 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 ~2,275 GDD — county provides 2,555 GDD Good fit

Sunchoke Planting Timeline — Benewah County, ID

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 – Jun 5
Harvest September 11 Sep 11 – Nov 6

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

146 days in Benewah County

Growing Tips for Sunchoke in Benewah County

Direct sow Sunchoke outdoors after May 08 in Benewah County when soil has warmed and frost danger has passed.

Your 146.0-day growing season in Benewah County is tight for Sunchoke (110.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Benewah County receives only 21" of rain annually. Sunchoke needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Benewah County, ID?

Benewah County is in Zone 6b with an average last frost of May 8. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benewah County, ID?

Benewah County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 8 and first fall frost is October 1.

🌱

Your Benewah County Garden Planner — Free

A 24-page printable planner built for Benewah County (Zone 6b). 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 Benewah County, ID. 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.