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When to plant Rue in Johnson County County,

Johnson County County sits in cold Zone 7a. Plant Rue April 14–April 28 for the single annual harvest; the October 21 first frost closes the window.

When to Plant Rue in Johnson County, IL

Johnson County, Illinois Zone 7a June

What to do in June

Here's what deserves your attention in Johnson County, Illinois this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 7
Avg. first frost October 21
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Bring in the rue

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong July, finish these tasks
  • First harvests: rue

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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.

Johnson County, Illinois is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 21, giving you a growing season of approximately 197 days.

At an elevation of 1,006 feet, Johnson County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Rue during the growing season.

Johnson County, IL (Zone 7a) Moderate season
197 days
Last Spring Frost April 7
197 growing days
First Fall Frost October 21
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Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Rue Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 10 🍅 Harvest: Jun 19 – Aug 21
Recommended (50%) ✓ Fits season (57 days to spare)
Transplant: Apr 14 🍅 Harvest: Jun 23 – Aug 25
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: Apr 28 🍅 Harvest: Jul 7 – Sep 8

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 Johnson County

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

Soil pH

Your soil pH (5.9–7.2) overlaps with Rue's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — Rue will thrive.

How to Plant Rue

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

Succession Planting Rue

3
successive plantings in your 197-day season

Sow every 8 weeks. Last sowing by Jul 23 to harvest before frost.

Rue Water Budget

Plant needs
0.5″/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 — 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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.8" 0" ✅ Rainfall sufficient
Aug 2.2" 4.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.2" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Johnson County). Supplement amounts are based on average rainfall — 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" — 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.

Rue needs ~1,400 GDD — county provides 3,447 GDD Excellent fit

Rue Planting Timeline — Johnson County, IL

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors April 14 Apr 14 – Apr 28
Harvest June 23 Jun 23 – Aug 25

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

197 days in Johnson County

Growing Tips for Rue in Johnson County

Direct sow Rue outdoors after April 07 in Johnson 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 Johnson County, IL?

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

What planting zone is Johnson County, IL?

Johnson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 21.

When should I plant Rue in Johnson County, ?

In Johnson County, , plant Rue after the last frost (around April 7) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Johnson County, for Rue?

Johnson County sits in USDA Zone 7a. Rue grows reliably in zones 4a through 9b, so it's a good fit here.

Can Rue grow in Johnson County's climate?

Yes — Rue grows well in Johnson County's temperate climate. Johnson County averages a 197-day frost-free season, with last frost around April 7 and first frost around October 21.

🌱

Your Johnson County Garden Planner — Free

A 22-page printable planner built for Johnson 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Johnson County, IL. 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.