When to plant Spinach in Kankakee, IL
Kankakee gardeners should plant Spinach between April 6 and April 27 in spring. With Kankakee's Zone 5b climate (last frost April 20), Spinach needs 35–50 days to mature — plant by August 25 for a full harvest. A second sowing from August 5 to August 19 extends the harvest into fall.
When to Plant Spinach in Kankakee, IL
Top priorities for Kankakee County, Illinois gardeners in July
Welcome to July in Zone 5b. These are the moves that will have the biggest impact on your growing season.
-
Bring in the spinach
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Get ahead of August
- Fall sowing: spinach
Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.
Kankakee, Illinois is in USDA Zone 5b. The average last spring frost is April 20 and the first fall frost is October 14, giving you a growing season of approximately 177 days.
At an elevation of 1,113 feet, Kankakee County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Spinach during the growing season.
Kankakee Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.8
Drainage
Well Drained
Spinach 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 Kankakee
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.1–6.8) is more acidic than Spinach prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Kankakee County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.9%) — Spinach will thrive.
How to Plant Spinach
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Aug 25 to harvest before frost.
For a dedicated fall crop, sow by Aug 05.
Spinach Water Budget
Monthly Watering Guide for Spinach
Spinach needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Spinach Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 2.8" | 0.2" | 💧 Light watering |
| Oct | 3" | 2.7" | 0.3" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Kankakee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Spinach 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.
Spinach Planting Timeline — Kankakee, IL
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 16 | Mar 16 – Mar 30 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Direct Sow | April 6 | Apr 6 – Apr 27 |
| Harvest | May 25 | May 25 – Jul 27 |
| Fall Sowing | August 5 | Aug 5 – Aug 19 |
Plant 0.5" 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 Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5b
📆 Growing Season
177 days in Kankakee County
Growing Tips for Spinach in Kankakee
Direct sow Spinach outdoors after April 20 in Kankakee County when soil has warmed and frost danger has passed.
Your generous 177.0-day season in Kankakee County allows multiple plantings of Spinach. Sow every 17.0 days for continuous harvest.
General growing tips
Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.
Recommended Spinach Varieties for Kankakee
Slow-bolting spinach for warm springs — best as fall crop here
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Wind pollinated — isolate 1/2 mile for purity. Easy to let bolt in heat.
Spinach in Other Locations
When should I plant Spinach in Kankakee, IL?
In Kankakee, IL, plant Spinach after the last frost (around April 20) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is Kankakee, IL for Spinach?
Kankakee sits in USDA Zone 5b. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.
Can Spinach grow in Kankakee's climate?
Yes — Spinach grows well in Kankakee's temperate climate. Kankakee averages a 177-day frost-free season, with last frost around April 20 and first frost around October 14.
Your Kankakee County Garden Planner — Free
A 22-page printable planner built for Kankakee 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.