When to Plant Hubbard Squash in Jefferson County, WI
This month in Jefferson County, Wisconsin
Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.
-
Move hubbard squash from tray to bed
Frost risk is low now in Jefferson County, Wisconsin. If you've been covering beds overnight, you can stop.
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Put hubbard squash seeds straight in the ground
These tolerate cool soil, so you're not gambling by sowing now.
A few tasks this May that'll pay off in June
- Starting indoors: hubbard squash
Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.
Jefferson 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 613 feet, Jefferson County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Hubbard Squash during the growing season.
Jefferson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.7
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 Jefferson County
How your county's soil matches Hubbard Squash's growing requirements.
Soil pH
Your soil pH (6.3–6.7) is within Hubbard Squash's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Jefferson County is excellent for Hubbard Squash — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Hubbard Squash.
Organic Matter
Organic matter is excellent (4.1%) — Hubbard Squash will thrive.
How to Plant Hubbard Squash
Plant Water Budget
Monthly Watering Guide for Hubbard Squash
Hubbard Squash needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Hubbard Squash Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Hubbard Squash 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.
Hubbard Squash Planting Timeline — Jefferson County, WI
Hubbard Squash Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | May 4 | May 4 – May 25 |
| Harvest | August 24 | Aug 24 – Sep 28 |
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 | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
100–120 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
168 days in Jefferson County
Growing Tips for Hubbard Squash in Jefferson County
Direct sow Hubbard Squash outdoors after April 27 in Jefferson County when soil has warmed and frost danger has passed.
Common pests for Hubbard Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Hubbard Squash in Other Locations
Frequently Asked Questions
When should I plant Hubbard Squash in Jefferson County, WI?
Jefferson County is in Zone 5b with an average last frost of April 27. Plan your Hubbard Squash planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, WI?
Jefferson County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 12.
Your Jefferson County Garden Planner — Free
A 24-page printable planner built for Jefferson 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.