When to plant Parsley in St. Clair County, IL
St. Clair County sits in USDA Zone 7a. Plant Parsley between March 19 (after last frost on April 2) and April 9. A second sowing from August 24 to September 7 extends the harvest into fall.
When to Plant Parsley in St. Clair County, IL
Your July gardening checklist
If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.
-
Pick parsley
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Before August arrives, get these ready
- Fall sowing: parsley
Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.
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 Parsley during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Parsley Planting Risk Windows
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 Parsley's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Parsley's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Clair County is excellent for Parsley — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Parsley will thrive.
How to Plant Parsley
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Parsley
Sow every 6.9 weeks. Last sowing by Aug 14 to harvest before frost.
For a dedicated fall crop, sow by Aug 24.
Parsley Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Parsley
Parsley needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Parsley Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.5" | 0.1" | 💧 Light watering |
| Nov | 2.6" | 2.4" | 0.2" | 💧 Light 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.
Parsley 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.
Parsley Planting Timeline — St. Clair County, IL
Parsley 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 |
| Harvest | May 28 | May 28 – Jul 30 |
| Fall Sowing | August 24 | Aug 24 – Sep 7 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
214 days in St. Clair County
Growing Tips for Parsley in St. Clair County
Direct sow Parsley outdoors after April 02 in St. Clair County when soil has warmed and frost danger has passed.
Common pests for Parsley in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Parsley in Other Locations
Frequently Asked Questions
When should I plant Parsley in St. Clair County, IL?
St. Clair County is in Zone 7a with an average last frost of April 2. Plan your Parsley 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.
When should I plant Parsley in St. Clair County, IL?
In St. Clair County, IL, plant Parsley after the last frost (around April 2) and before the first frost (around November 2). Best results when soil holds above 50°F.
What growing zone is St. Clair County, IL for Parsley?
St. Clair County sits in USDA Zone 7a. Parsley grows reliably in zones 2a through 10b, so it's a good fit here.
Can Parsley grow in St. Clair County's climate?
Yes — Parsley grows well in St. Clair County's temperate climate. St. Clair County averages a 214-day frost-free season, with last frost around April 2 and first frost around November 2.
Your St. Clair County Garden Planner — Free
A 22-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.