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When to Plant Arugula in Walworth County, SD

Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.

Walworth County, South Dakota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is October 1, giving you a growing season of approximately 144 days.

At an elevation of 1,070 feet, Walworth County receives approximately 30.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Arugula to ensure they mature before fall.

Walworth County, SD (Zone 4a) Short season
144 days
Last Spring Frost May 10
144 growing days
First Fall Frost October 1

Walworth County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jun 5 – Aug 7
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jun 14 – Aug 16
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jun 23 – Aug 25

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 Walworth County

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

Soil pH

Your soil pH (6.5โ€“7.8) is more alkaline than Arugula prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Walworth County is excellent for Arugula โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Arugula.

How to Plant Arugula

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Arugula

5
successive plantings in your 144-day season

Sow every 3.4 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Jul 09.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Arugula

Arugula needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Arugula Needs Rainfall You Supplement Action
Jan โ€” 2.1" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 2.9" 0" โ„๏ธ Dormant
May 2.6" 3.8" 0" โœ… Rainfall sufficient
Jun 2.6" 1.9" 0.7" ๐Ÿ’ง Light watering
Jul 2.6" 2.7" 0" โœ… Rainfall sufficient
Aug 2.6" 2.8" 0" โœ… Rainfall sufficient
Sep 2.6" 2.6" 0" โœ… Rainfall sufficient
Oct 2.6" 2.8" 0" โœ… Rainfall sufficient
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Walworth County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Arugula 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" โ€” every day above 50ยฐF 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.

Arugula needs ~460 GDD — county provides 1,656 GDD Excellent fit

Arugula Planting Timeline โ€” Walworth County, SD

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 โ€“ Apr 12
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow May 3 May 3 โ€“ May 24
Harvest June 14 Jun 14 โ€“ Aug 16
Fall Sowing July 9 Jul 9 โ€“ Jul 23

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

30โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

144 days in Walworth County

Growing Tips for Arugula in Walworth County

Direct sow Arugula outdoors after May 10 in Walworth County when soil has warmed and frost danger has passed.

Your generous 144.0-day season in Walworth County allows multiple plantings of Arugula. Sow every 15.0 days for continuous harvest.

Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Arugula in Walworth County, SD?

Walworth County is in Zone 4a with an average last frost of May 10. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Walworth County, SD?

Walworth County, South Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Walworth County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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