When to Plant Shallot in Des Moines County, IA
May in the garden — Des Moines County, Iowa
Welcome to May in Zone 6a. These are the moves that will have the biggest impact on your growing season.
-
Start shallot under lights
These need a head start before your last frost (April 17). Sow into cells now so you're ready to transplant in a few weeks.
Shallots are a gourmet allium prized for their complex, sweet, and mild flavor. Each bulb multiplies into a cluster, making them easy and rewarding to grow.
Des Moines County, Iowa is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 16, giving you a growing season of approximately 182 days.
At an elevation of 606 feet, Des Moines County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Shallot during the growing season.
Des Moines County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.7
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 Des Moines County
How your county's soil matches Shallot's growing requirements.
Soil pH
Your soil pH (6.2–6.7) is within Shallot's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Des Moines County is excellent for Shallot — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Shallot.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Shallot.
How to Plant Shallot
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Shallot
Shallot needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Shallot Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.3" | 1" | 💧 Light watering |
| May | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jun | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Des Moines County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Shallot 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.
Shallot Planting Timeline — Des Moines County, IA
Shallot Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Direct Sow | April 3 | Apr 3 – Apr 24 |
| Harvest | July 17 | Jul 17 – Sep 4 |
| Fall Sowing | August 7 | Aug 7 – Aug 21 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
182 days in Des Moines County
Growing Tips for Shallot in Des Moines County
Direct sow Shallot outdoors after April 17 in Des Moines County when soil has warmed and frost danger has passed.
Common pests for Shallot in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant sets in fall for spring harvest or early spring for summer harvest. Mulch heavily if overwintering. Harvest when tops brown and dry, then cure for storage.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Shallot in Other Locations
Frequently Asked Questions
When should I plant Shallot in Des Moines County, IA?
Des Moines County is in Zone 6a with an average last frost of April 17. Plan your Shallot planting based on this frost date — see the calendar above for exact timing.
What planting zone is Des Moines County, IA?
Des Moines County, Iowa is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 16.
Your Des Moines County Garden Planner — Free
A 24-page printable planner built for Des Moines County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.