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When to Plant Rue in Union County, IN

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.

Union County, Indiana is in USDA Zone 6a. The average last spring frost is April 25 and the first fall frost is October 17, giving you a growing season of approximately 175 days.

At an elevation of 506 feet, Union County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Rue during the growing season.

Union County, IN (Zone 6a) Moderate season
175 days
Last Spring Frost April 25
175 growing days
First Fall Frost October 17

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 3 – Sep 4
Recommended (50%) ✓ Fits season (35 days to spare)
Transplant: May 2 🍅 Harvest: Jul 11 – Sep 12
Safe Start (90%) ✓ Fits season (31 days to spare)
Transplant: May 16 🍅 Harvest: Jul 25 – Sep 26

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 Union County

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

Soil pH

Your soil pH (5.7โ€“7.2) overlaps with Rue's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Rue.

Organic Matter

Organic matter is excellent (4.1%) 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 175-day season

Sow every 8 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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€” 1.2" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr 2.2" 3" 0" โœ… Rainfall sufficient
May 2.2" 4.4" 0" โœ… Rainfall sufficient
Jun 2.2" 3.6" 0" โœ… Rainfall sufficient
Jul 2.2" 3.7" 0" โœ… Rainfall sufficient
Aug 2.2" 3.1" 0" โœ… Rainfall sufficient
Sep 2.2" 3.3" 0" โœ… Rainfall sufficient
Oct 2.2" 2.9" 0" โœ… Rainfall sufficient
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Union 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 ~1,400 GDD — county provides 3,062 GDD Excellent fit

Rue Planting Timeline โ€” Union County, IN

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors May 2 May 2 โ€“ May 16
Harvest July 11 Jul 11 โ€“ Sep 12

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 6a

๐Ÿ“† Growing Season

175 days in Union County

Growing Tips for Rue in Union County

Direct sow Rue outdoors after April 25 in Union 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 Union County, IN?

Union County is in Zone 6a with an average last frost of April 25. Plan your Rue planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, IN?

Union County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Union County gardeners in Zone 6a 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 Union County, IN. Local conditions may vary. Last updated: April 2026.