When to Plant Sweet Potatoes in Fayette County, IA
What to do in May
Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.
-
Transplant sweet potatoes outside
Your last frost (May 5) has passed. These warm-season crops can handle outdoor soil now.
-
Scatter sweet potatoes into prepared beds
Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.
Before June arrives, get these ready
- Starting indoors: sweet potatoes
Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.
Fayette County, Iowa is in USDA Zone 5a. The average last spring frost is May 5 and the first fall frost is October 5, giving you a growing season of approximately 153 days.
At an elevation of 1,228 feet, Fayette County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Sweet Potatoes to ensure they mature before fall.
Fayette County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.8
Drainage
Well Drained
Plant 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 Fayette County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (6.2–6.8) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Fayette County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Sweet Potatoes will thrive.
How to Plant Sweet Potatoes
Plant Water Budget
Monthly Watering Guide for Sweet Potatoes
Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sweet Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 2.1" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 4.5" | 0" | ❄️ Dormant |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Fayette County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Potatoes 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.
Sweet Potatoes Planting Timeline — Fayette County, IA
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | May 19 | May 19 – Jun 2 |
| Direct Sow | May 12 | May 12 – Jun 2 |
| Harvest | August 18 | Aug 18 – Oct 6 |
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 | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
153 days in Fayette County
Growing Tips for Sweet Potatoes in Fayette County
Direct sow Sweet Potatoes outdoors after May 05 in Fayette County when soil has warmed and frost danger has passed.
General growing tips
Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Fayette County, IA?
Fayette County is in Zone 5a with an average last frost of May 5. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fayette County, IA?
Fayette County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 5 and first fall frost is October 5.
Your Fayette County Garden Planner — Free
A 24-page printable planner built for Fayette 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.