When to plant Tomatillo in St. Clair County County,
St. Clair County County's spring Tomatillo window runs April 9 through April 30. most warm-season crops establish quickly once soil holds above 60°F.
When to Plant Tomatillo in St. Clair County, IL
What to do in June
Here's what deserves your attention in St. Clair County, Illinois this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Collect tomatillo at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
July prep starts now
- First harvests: tomatillo
Tomatillos are a Mexican staple that produces tart, green fruits enclosed in papery husks. They are essential for salsa verde and green sauces.
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 Tomatillo during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Tomatillo 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 Tomatillo's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Tomatillo's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Clair County is excellent for Tomatillo — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Tomatillo will thrive.
How to Plant Tomatillo
Succession Planting Tomatillo
Sow every 6.9 weeks. Last sowing by Aug 09 to harvest before frost.
Tomatillo Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Tomatillo
Tomatillo needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.
| Month | Tomatillo Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 4.8" | 3.2" | 1.6" | 💧 Light watering |
| May | 4.8" | 3.8" | 1" | 💧 Light watering |
| Jun | 4.8" | 4" | 0.8" | 💧 Light watering |
| Jul | 4.8" | 3.8" | 1" | 💧 Light watering |
| Aug | 4.8" | 3.9" | 0.9" | 💧 Light watering |
| Sep | 4.8" | 3.3" | 1.5" | 💧 Light watering |
| Oct | 4.8" | 2.5" | 2.3" | 💧 Light watering |
| Nov | 4.8" | 2.4" | 2.4" | 🚿 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.
Tomatillo 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.
Tomatillo Planting Timeline — St. Clair County, IL
Tomatillo Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 12 | Feb 12 – Feb 26 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Direct Sow | April 9 | Apr 9 – Apr 30 |
| Harvest | June 18 | Jun 18 – Aug 27 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.1"/week · 1-2 times/week
📅 Days to Maturity
60–85 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
214 days in St. Clair County
Growing Tips for Tomatillo in St. Clair County
Direct sow Tomatillo outdoors after April 02 in St. Clair County when soil has warmed and frost danger has passed.
Common pests for Tomatillo in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Plant at least two plants for cross-pollination. Harvest when fruits fill the husk and it begins to split.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Tomatillo in Other Locations
Frequently Asked Questions
When should I plant Tomatillo in St. Clair County, IL?
St. Clair County is in Zone 7a with an average last frost of April 2. Plan your Tomatillo 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 Tomatillo in St. Clair County County, ?
In St. Clair County County, , plant Tomatillo 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 County, for Tomatillo?
St. Clair County County sits in USDA Zone 7a. Tomatillo grows reliably in zones 4a through 11b, so it's a good fit here.
Can Tomatillo grow in St. Clair County County's climate?
Yes — Tomatillo grows well in St. Clair County County's temperate climate. St. Clair County 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.