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When to Plant Rue in Dunn County, WI

Rue is a bitter, aromatic perennial herb with bluish-green foliage used historically in medicine and as a pest deterrent. Handle with care as its sap can cause skin irritation.

Dunn County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 29, giving you a growing season of approximately 140 days.

At an elevation of 1,221 feet, Dunn County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Rue to ensure they mature before fall.

Dunn County, WI (Zone 4a) Short season
140 days
Last Spring Frost May 12
140 growing days
First Fall Frost September 29

Dunn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Transplant: May 10 🍅 Harvest: Jul 19 – Sep 20
Recommended (50%) ✓ Fits season (0 days to spare)
Transplant: May 19 🍅 Harvest: Jul 28 – Sep 29
Safe Start (90%) ✓ Fits season (6 days to spare)
Transplant: May 27 🍅 Harvest: Aug 5 – Oct 7

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 Dunn County

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

Soil pH

Your soil pH (5.9โ€“6.7) overlaps with Rue's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Rue.

How to Plant Rue

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rue

2
successive plantings in your 140-day season

Sow every 8 weeks. Last sowing by Jul 01 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 Rue

Rue needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Rue Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr โ€” 3.2" 0" โ„๏ธ Dormant
May 2.2" 3.8" 0" โœ… Rainfall sufficient
Jun 2.2" 4.1" 0" โœ… Rainfall sufficient
Jul 2.2" 4" 0" โœ… Rainfall sufficient
Aug 2.2" 4.2" 0" โœ… Rainfall sufficient
Sep 2.2" 2.7" 0" โœ… Rainfall sufficient
Oct โ€” 2.8" 0" โ„๏ธ Dormant
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

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

Rue 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.

Rue needs ~860 GDD — county provides 1,505 GDD Excellent fit

Rue Planting Timeline โ€” Dunn County, WI

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors May 19 May 19 โ€“ Jun 2
Harvest July 28 Jul 28 โ€“ Sep 29

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

140 days in Dunn County

Growing Tips for Rue in Dunn County

Direct sow Rue outdoors after May 12 in Dunn County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow. Plant in well-drained soil. Wear gloves when handling as sap can cause phytophotodermatitis. Prune in early spring.

Companion Planting

Good Companions

Avoid Planting Near

  • Basil
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rue in Dunn County, WI?

Dunn County is in Zone 4a with an average last frost of May 12. Plan your Rue planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dunn County, WI?

Dunn County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dunn 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 Dunn County, WI. Local conditions may vary. Last updated: April 2026.