When to plant Hubbard Squash in Castleton, IL
Hubbard Squash planted in Castleton between April 28 and May 19 matures in 100–120 days — well before the October 12 first frost.
When to Plant Hubbard Squash in Castleton, IL
What to do in June
Your Stark County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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.
Castleton, Illinois is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 12, giving you a growing season of approximately 174 days.
At an elevation of 1,071 feet, Stark County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Hubbard Squash to ensure they mature before fall.
Castleton Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.9
Drainage
Well Drained
Hubbard Squash 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 Castleton
How your county's soil matches Hubbard Squash's growing requirements.
Soil pH
Your soil pH (6.0–6.9) is within Hubbard Squash's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Stark County is excellent for Hubbard Squash — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Hubbard Squash will thrive.
How to Plant Hubbard Squash
Hubbard Squash 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Stark 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 — Castleton, IL
Hubbard Squash Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | August 18 | Aug 18 – Sep 22 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| 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 · Only during dry spells
📅 Days to Maturity
100–120 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
174 days in Stark County
Growing Tips for Hubbard Squash in Castleton
Direct sow Hubbard Squash outdoors after April 21 in Stark 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
When should I plant Hubbard Squash in Castleton, IL?
In Castleton, IL, plant Hubbard Squash after the last frost (around April 21) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Castleton, IL for Hubbard Squash?
Castleton sits in USDA Zone 5b. Hubbard Squash grows reliably in zones 3a through 10b, so it's a good fit here.
Can Hubbard Squash grow in Castleton's climate?
Yes — Hubbard Squash grows well in Castleton's temperate climate. Castleton averages a 174-day frost-free season, with last frost around April 21 and first frost around October 12.
Your Stark County Garden Planner — Free
A 22-page printable planner built for Stark 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.