Blog

When to plant Sunchoke in Howell County, MO

Howell County's short 199-day growing season means one Sunchoke planting between April 23 and May 7. No fall crop in Zone 7a.

When to Plant Sunchoke in Howell County, MO

Howell County, Missouri Zone 7a June

June in the garden — Howell County, Missouri

Welcome to June in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 9
Avg. first frost October 25
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.5 hrs

Instant PDF download. No spam, unsubscribe any time.

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

Howell County, Missouri is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 696 feet, Howell County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Sunchoke during the growing season.

Howell County, MO (Zone 7a) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Howell County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.6

Drainage

Well Drained

Sunchoke Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Transplant: Apr 14 🍅 Harvest: Aug 4 – Sep 29
Recommended (50%) ✓ Fits season (17 days to spare)
Transplant: Apr 23 🍅 Harvest: Aug 13 – Oct 8
Safe Start (90%) ✓ Fits season (21 days to spare)
Transplant: May 6 🍅 Harvest: Aug 26 – Oct 21

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 Howell County

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

Soil pH

Your soil pH (5.7–6.6) overlaps with Sunchoke's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Sunchoke.

How to Plant Sunchoke

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

Sunchoke Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 488 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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Howell 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 ~1,982 GDD — county provides 3,034 GDD Excellent fit

Sunchoke Planting Timeline — Howell County, MO

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 – May 7
Harvest August 13 Aug 13 – Oct 8

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

199 days in Howell County

Growing Tips for Sunchoke in Howell County

Direct sow Sunchoke outdoors after April 09 in Howell 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 Howell County, MO?

Howell County is in Zone 7a with an average last frost of April 9. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Howell County, MO?

Howell County, Missouri is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 25.

When should I plant Sunchoke in Howell County, MO?

In Howell County, MO, plant Sunchoke after the last frost (around April 9) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Howell County, MO for Sunchoke?

Howell County sits in USDA Zone 7a. Sunchoke grows reliably in zones 3a through 9b, so it's a good fit here.

Can Sunchoke grow in Howell County's climate?

Yes — Sunchoke grows well in Howell County's temperate climate. Howell County averages a 199-day frost-free season, with last frost around April 9 and first frost around October 25.

🌱

Your Howell County Garden Planner — Free

A 22-page printable planner built for Howell County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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