When to plant Arugula in Downs, IL
The best window to plant Arugula in Downs, is April 4–April 25, when soil warms to 50°F. Last frost typically hits April 18; first frost October 18. A second sowing from August 9 to August 23 extends the harvest into fall.
When to Plant Arugula in Downs, IL
August in the garden — McLean County, Illinois
Here's what deserves your attention in McLean County, Illinois this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
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Direct-sow arugula for cool weather
Fall crops get sweeter with a light frost. Don't be afraid of cool nights.
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.
Downs, Illinois is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 18, giving you a growing season of approximately 183 days.
At an elevation of 1,024 feet, McLean County receives approximately 31.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Arugula during the growing season.
Downs Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
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 Downs
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (6.0–7.0) is within Arugula's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in McLean County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — 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 29 to harvest before frost.
For a dedicated fall crop, sow by Aug 09.
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in McLean 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 — Downs, IL
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 4 | Apr 4 – Apr 25 |
| Harvest | May 23 | May 23 – Jul 25 |
| Fall Sowing | August 9 | Aug 9 – Aug 23 |
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 6a
📆 Growing Season
183 days in McLean County
Growing Tips for Arugula in Downs
Direct sow Arugula outdoors after April 18 in McLean County when soil has warmed and frost danger has passed.
Your generous 183.0-day season in McLean 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 Downs, IL?
In Downs, IL, plant Arugula after the last frost (around April 18) and before the first frost (around October 18). Best results when soil holds above 50°F.
What growing zone is Downs, IL for Arugula?
Downs sits in USDA Zone 6a. Arugula grows reliably in zones 3a through 11b, so it's a good fit here.
Can Arugula grow in Downs's climate?
Yes — Arugula grows well in Downs's temperate climate. Downs averages a 183-day frost-free season, with last frost around April 18 and first frost around October 18.
Your McLean County Garden Planner — Free
A 22-page printable planner built for McLean County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.