When to plant Mint in Decatur County, IA
Plant Mint in Decatur County during the brief April 30–May 14 window. With 172 frost-free days, fall plantings can't mature before October 12.
When to Plant Mint in Decatur County, IA
Your July planting checklist for Decatur County, Iowa
Your garden in Decatur County, Iowa is working on a schedule, even when you're not. Here's where you should be this July.
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It's harvest week for mint
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in August — start thinking about
- First harvests: mint
Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.
Decatur County, Iowa is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.
At an elevation of 541 feet, Decatur County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Mint to ensure they mature before fall.
Decatur County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Mint 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 Decatur County
How your county's soil matches Mint's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Mint's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Decatur County is excellent for Mint — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Mint is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is excellent (4.2%) — Mint will thrive.
How to Plant Mint
Succession Planting Mint
Sow every 6.9 weeks. Last sowing by Jul 14 to harvest before frost.
Mint Water Budget
Monthly Watering Guide for Mint
Mint needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Mint Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 3" | 3.5" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 2.8" | 0.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Decatur County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mint 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.
Mint Planting Timeline — Decatur County, IA
Mint Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Harvest | July 2 | Jul 2 – Sep 10 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
172 days in Decatur County
Growing Tips for Mint in Decatur County
Direct sow Mint outdoors after April 23 in Decatur County when soil has warmed and frost danger has passed.
General growing tips
Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mint in Other Locations
Frequently Asked Questions
When should I plant Mint in Decatur County, IA?
Decatur County is in Zone 5b with an average last frost of April 23. Plan your Mint planting based on this frost date — see the calendar above for exact timing.
What planting zone is Decatur County, IA?
Decatur County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 12.
When should I plant Mint in Decatur County, IA?
In Decatur County, IA, plant Mint after the last frost (around April 23) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Decatur County, IA for Mint?
Decatur County sits in USDA Zone 5b. Mint grows reliably in zones 3a through 10b, so it's a good fit here.
Can Mint grow in Decatur County's climate?
Yes — Mint grows well in Decatur County's temperate climate. Decatur County averages a 172-day frost-free season, with last frost around April 23 and first frost around October 12.
Your Decatur County Garden Planner — Free
A 22-page printable planner built for Decatur County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.