When to plant Tomatillo in Mapleton, IA
In Mapleton, plant Tomatillo in spring between May 3 and May 24, once soil temps hold above 50°F. Mapleton's last frost averages April 26, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 60–85 days before the first frost on October 10.
When to Plant Tomatillo in Mapleton, IA
August in Monona County, Iowa — your action list
Your garden in Monona County, Iowa is working on a schedule, even when you're not. Here's where you should be this August.
-
Pick tomatillo
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Before September arrives, get these ready
- 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.
Mapleton, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 10, giving you a growing season of approximately 167 days.
At an elevation of 732 feet, Monona County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Tomatillo to ensure they mature before fall.
Mapleton Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-7.1
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 Mapleton
How your county's soil matches Tomatillo's growing requirements.
Soil pH
Your soil pH (5.7–7.1) overlaps with Tomatillo's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Monona County is excellent for Tomatillo — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Tomatillo.
Organic Matter
Organic matter is excellent (4.4%) — Tomatillo will thrive.
How to Plant Tomatillo
Succession Planting Tomatillo
Sow every 6.9 weeks. Last sowing by Jul 17 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 4.8" | 3" | 1.8" | 💧 Light watering |
| May | 4.8" | 3.8" | 1" | 💧 Light watering |
| Jun | 4.8" | 4.3" | 0.5" | 💧 Light watering |
| Jul | 4.8" | 4" | 0.8" | 💧 Light watering |
| Aug | 4.8" | 4.2" | 0.6" | 💧 Light watering |
| Sep | 4.8" | 2.8" | 2" | 💧 Light watering |
| Oct | 4.8" | 3" | 1.8" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Monona 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 — Mapleton, IA
Tomatillo Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | May 3 | May 3 – May 24 |
| Harvest | July 12 | Jul 12 – Sep 20 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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 5a
📆 Growing Season
167 days in Monona County
Growing Tips for Tomatillo in Mapleton
Direct sow Tomatillo outdoors after April 26 in Monona 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
When should I plant Tomatillo in Mapleton, IA?
In Mapleton, IA, plant Tomatillo after the last frost (around April 26) and before the first frost (around October 10). Best results when soil holds above 50°F.
What growing zone is Mapleton, IA for Tomatillo?
Mapleton sits in USDA Zone 5a. Tomatillo grows reliably in zones 4a through 11b, so it's a good fit here.
Can Tomatillo grow in Mapleton's climate?
Yes — Tomatillo grows well in Mapleton's temperate climate. Mapleton averages a 167-day frost-free season, with last frost around April 26 and first frost around October 10.
Your Monona County Garden Planner — Free
A 22-page printable planner built for Monona County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.