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When to Plant Angelica in St. Clair County, IL

St. Clair County, Illinois Zone 7a May

St. Clair County, Illinois gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in St. Clair County, Illinois.

Avg. last frost April 2
Avg. first frost November 2
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Fire up the seed-starting tray: angelica

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

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Angelica is a dramatic biennial herb that can reach 6 feet tall with large compound leaves and globe-shaped flower clusters. All parts are edible with a sweet, celery-like flavor.

St. Clair County, Illinois is in USDA Zone 7a. The average last spring frost is April 2 and the first fall frost is November 2, giving you a growing season of approximately 214 days.

At an elevation of 711 feet, St. Clair County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Angelica during the growing season.

St. Clair County, IL (Zone 7a) Long season
214 days
Last Spring Frost April 2
214 growing days
First Fall Frost November 2
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St. Clair County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Start indoors: Feb 19 Transplant: Mar 19
Recommended (50%) ✓ Fits season
Start indoors: Feb 26 Transplant: Mar 26
Safe Start (90%) ✓ Fits season
Start indoors: Mar 13 Transplant: Apr 10

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 St. Clair County

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

Soil pH

Your soil pH (6.0–7.3) overlaps with Angelica's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Angelica will thrive.

How to Plant Angelica

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,899 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Angelica

Angelica needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Angelica Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 6.5" 3.2" 3.3" 🚿 Regular watering
May 6.5" 3.8" 2.7" 💧 Light watering
Jun 6.5" 4" 2.5" 💧 Light watering
Jul 6.5" 3.8" 2.7" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 3.3" 3.2" 💧 Light watering
Oct 6.5" 2.5" 4" 🚿 Regular watering
Nov 6.5" 2.4" 4.1" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in St. Clair County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Angelica 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.

Angelica needs ~9,171 GDD — county provides 3,584 GDD May not mature

Angelica Planting Timeline — St. Clair County, IL

Angelica Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors March 26 Mar 26 – Apr 9
Direct Sow March 19 Mar 19 – Apr 9
Fall Sowing August 24 Aug 24 – Sep 7

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May
June
July
August Fall Sowing
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

214 days in St. Clair County

Growing Tips for Angelica in St. Clair County

Direct sow Angelica outdoors after April 02 in St. Clair County when soil has warmed and frost danger has passed.

Your 214.0-day growing season in St. Clair County is tight for Angelica (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Angelica in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow fresh seeds in fall for spring germination. Provide rich, moist soil and partial shade. Harvest stems in the second year before flowering for candying or flavoring.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Angelica in St. Clair County, IL?

St. Clair County is in Zone 7a with an average last frost of April 2. Plan your Angelica planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Clair County, IL?

St. Clair County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 2 and first fall frost is November 2.

🌱

Your St. Clair County Garden Planner — Free

A 24-page printable planner built for St. Clair 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 St. Clair County, IL. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.