When to plant Arugula in Castleton,
Plant Arugula in Castleton, when soil hits 50°F — usually April 7. Continue planting through April 28 for the spring crop. A second sowing from August 3 to August 17 extends the harvest into fall.
When to Plant Arugula in Castleton, IL
Your June gardening checklist
Here's what deserves your attention in Castleton, IL this month. Everything below is tailored to Zone 5b and timed around your local frost dates.
-
Harvest arugula as they ripen
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
July prep starts now
- First harvests: arugula
Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.
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 Arugula to ensure they mature before fall.
Castleton Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.9
Drainage
Well Drained
Arugula 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 Arugula's growing requirements.
Soil pH
Your soil pH (6.0–6.9) is within Arugula's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Stark County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Arugula will thrive.
How to Plant Arugula
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Arugula
Sow every 3.4 weeks. Last sowing by Aug 23 to harvest before frost.
For a dedicated fall crop, sow by Aug 03.
Arugula Water Budget
Monthly Watering Guide for Arugula
Arugula needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Arugula Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| 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.
Arugula 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.
Arugula Planting Timeline — Castleton, IL
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Harvest | May 26 | May 26 – Jul 28 |
| 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 | 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
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
174 days in Stark County
Growing Tips for Arugula in Castleton
Direct sow Arugula outdoors after April 21 in Stark County when soil has warmed and frost danger has passed.
Your generous 174.0-day season in Stark County allows multiple plantings of Arugula. Sow every 15.0 days for continuous harvest.
Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Arugula in Other Locations
When should I plant Arugula in Castleton, ?
In Castleton, , plant Arugula 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, for Arugula?
Castleton sits in USDA Zone 5b. Arugula grows reliably in zones 3a through 11b, so it's a good fit here.
Can Arugula grow in Castleton's climate?
Yes — Arugula 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.