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When to Plant Rue in Mitchell County, IA

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.

Mitchell County, Iowa is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 7, giving you a growing season of approximately 157 days.

At an elevation of 506 feet, Mitchell County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Rue to ensure they mature before fall.

Mitchell County, IA (Zone 4b) Moderate season
157 days
Last Spring Frost May 3
157 growing days
First Fall Frost October 7

Mitchell County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Transplant: May 4 🍅 Harvest: Jul 13 – Sep 14
Recommended (50%) ✓ Fits season (17 days to spare)
Transplant: May 10 🍅 Harvest: Jul 19 – Sep 20
Safe Start (90%) ✓ Fits season (14 days to spare)
Transplant: May 22 🍅 Harvest: Jul 31 – Oct 2

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 Mitchell County

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

Soil pH

Your soil pH (5.9โ€“7.3) overlaps with Rue's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) โ€” Rue will thrive.

How to Plant Rue

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

Succession Planting Rue

2
successive plantings in your 157-day season

Sow every 8 weeks. Last sowing by Jul 09 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

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€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 3.3" 0" โ„๏ธ Dormant
May 2.2" 4" 0" โœ… Rainfall sufficient
Jun 2.2" 5.1" 0" โœ… Rainfall sufficient
Jul 2.2" 3.9" 0" โœ… Rainfall sufficient
Aug 2.2" 3.9" 0" โœ… Rainfall sufficient
Sep 2.2" 2.9" 0" โœ… Rainfall sufficient
Oct 2.2" 2.4" 0" โœ… Rainfall sufficient
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Mitchell 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 ~1,040 GDD — county provides 2,041 GDD Excellent fit

Rue Planting Timeline โ€” Mitchell County, IA

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors May 10 May 10 โ€“ May 24
Harvest July 19 Jul 19 โ€“ Sep 20

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 โ€”
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 4b

๐Ÿ“† Growing Season

157 days in Mitchell County

Growing Tips for Rue in Mitchell County

Direct sow Rue outdoors after May 03 in Mitchell 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 Mitchell County, IA?

Mitchell County is in Zone 4b with an average last frost of May 3. Plan your Rue planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mitchell County, IA?

Mitchell County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mitchell County gardeners in Zone 4b 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 Mitchell County, IA. Local conditions may vary. Last updated: April 2026.