When to Plant Scallions in Waukesha County, WI
May to-do list for Waukesha County, Wisconsin
Your garden in Waukesha County, Wisconsin is working on a schedule, even when you're not. Here's where you should be this May.
June prep starts now
- Starting indoors: scallions
- First harvests: scallions
Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.
Waukesha County, Wisconsin is in USDA Zone 5b. The average last spring frost is April 27 and the first fall frost is October 12, giving you a growing season of approximately 168 days.
At an elevation of 1,352 feet, Waukesha County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Scallions to ensure they mature before fall.
Waukesha County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.3
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 Waukesha County
How your county's soil matches Scallions's growing requirements.
Soil pH
Your soil pH (6.1–7.3) overlaps with Scallions's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Waukesha County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Scallions.
Organic Matter
Organic matter is excellent (4.2%) — Scallions will thrive.
How to Plant Scallions
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Scallions
Sow every 5.7 weeks. Last sowing by Aug 03 to harvest before frost.
For a dedicated fall crop, sow by Aug 03.
Plant Water Budget
Monthly Watering Guide for Scallions
Scallions needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Scallions Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| May | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4" | 0.3" | 💧 Light watering |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Waukesha County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Scallions 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.
Scallions Planting Timeline — Waukesha County, WI
Scallions Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | April 27 | Apr 27 – May 11 |
| Direct Sow | April 13 | Apr 13 – May 4 |
| Harvest | June 22 | Jun 22 – Jul 20 |
| Fall Sowing | August 3 | Aug 3 – Aug 17 |
Plant 0.5" 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 | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
168 days in Waukesha County
Growing Tips for Scallions in Waukesha County
Direct sow Scallions outdoors after April 27 in Waukesha County when soil has warmed and frost danger has passed.
Common pests for Scallions in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Scallions in Other Locations
Frequently Asked Questions
When should I plant Scallions in Waukesha County, WI?
Waukesha County is in Zone 5b with an average last frost of April 27. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.
What planting zone is Waukesha County, WI?
Waukesha County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 12.
Your Waukesha County Garden Planner — Free
A 24-page printable planner built for Waukesha 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.