When to Plant Pumpkin in Lyon County, IA
Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.
Lyon County, Iowa is in USDA Zone 4b. The average last spring frost is May 2 and the first fall frost is October 2, giving you a growing season of approximately 153 days.
At an elevation of 1,045 feet, Lyon County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.
Lyon County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.8
Drainage
Well Drained
Monthly Watering Guide for Pumpkin
Pumpkin needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Pumpkin Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 3.2" | 0" | ❄️ Dormant |
| May | 4.3" | 3" | 1.3" | 💧 Light watering |
| Jun | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Lyon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Pumpkin Planting Timeline — Lyon County, IA
Pumpkin Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | May 23 | May 23 – Jun 6 |
| Direct Sow | May 16 | May 16 – Jun 6 |
| Harvest | August 22 | Aug 22 – Oct 10 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| 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
Moderate — regular watering
📅 Days to Maturity
85–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
153 days in Lyon County
Growing Tips for Lyon County
Direct sow on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Pumpkin in Other Locations
Frequently Asked Questions
When should I plant Pumpkin in Lyon County, IA?
Lyon County is in Zone 4b with an average last frost of May 2. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lyon County, IA?
Lyon County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 2 and first fall frost is October 2.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Lyon County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.