When to Plant Shallot in Dubuque County, IA
Dubuque County, Iowa gardeners: here's your May plan
Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.
To set up a strong June, finish these tasks
- Starting indoors: shallot
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.
Dubuque County, Iowa is in USDA Zone 5a. The average last spring frost is April 29 and the first fall frost is October 9, giving you a growing season of approximately 163 days.
At an elevation of 1,243 feet, Dubuque County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Shallot to ensure they mature before fall.
Dubuque County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.3
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 Dubuque County
How your county's soil matches Shallot's growing requirements.
Soil pH
Your soil pH (5.8–7.3) overlaps with Shallot's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Dubuque 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 (3.9%). 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Dubuque 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 — Dubuque County, IA
Shallot Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 25 | Mar 25 – Apr 8 |
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Direct Sow | April 15 | Apr 15 – May 6 |
| Harvest | July 29 | Jul 29 – Sep 16 |
| Fall Sowing | July 31 | Jul 31 – Aug 14 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing 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: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
163 days in Dubuque County
Growing Tips for Shallot in Dubuque County
Direct sow Shallot outdoors after April 29 in Dubuque 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 Dubuque County, IA?
Dubuque County is in Zone 5a with an average last frost of April 29. Plan your Shallot planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dubuque County, IA?
Dubuque County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 29 and first fall frost is October 9.
Your Dubuque County Garden Planner — Free
A 24-page printable planner built for Dubuque 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.