When to plant Arugula in Larimer County, CO
Aim to plant Arugula in Larimer County on or after April 18; the window stays open through May 9. Larimer County's 157-day frost-free season gives you a single solid spring crop with a brief fall option. A second sowing from July 28 to August 11 extends the harvest into fall.
When to Plant Arugula in Larimer County, CO
Your July gardening checklist
If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.
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Pick arugula
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
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Direct-sow arugula for cool weather
Count back from your first frost (October 6) — these need to mature before the cold arrives.
Looking ahead to August
- 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.
Larimer County, Colorado is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.
At an elevation of 7,108 feet, Larimer County receives approximately 23.4 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Arugula to ensure they mature before fall.
Larimer County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.2
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 Larimer County
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (6.4–8.2) is more alkaline than Arugula prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Larimer County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Arugula.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Arugula.
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 17 to harvest before frost.
For a dedicated fall crop, sow by Jul 28.
Arugula Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 2.6" | 2.5" | 0.1" | 💧 Light watering |
| Jun | 2.6" | 1.9" | 0.7" | 💧 Light watering |
| Jul | 2.6" | 2.3" | 0.3" | 💧 Light watering |
| Aug | 2.6" | 2.5" | 0.1" | 💧 Light watering |
| Sep | 2.6" | 2" | 0.6" | 💧 Light watering |
| Oct | 2.6" | 1.9" | 0.7" | 💧 Light watering |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Larimer 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 — Larimer County, CO
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 28 | Mar 28 – Apr 11 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Harvest | June 6 | Jun 6 – Aug 8 |
| Fall Sowing | July 28 | Jul 28 – Aug 11 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · Only during dry spells
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
157 days in Larimer County
Growing Tips for Arugula in Larimer County
Direct sow Arugula outdoors after May 02 in Larimer County when soil has warmed and frost danger has passed.
Your generous 157.0-day season in Larimer 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
Frequently Asked Questions
When should I plant Arugula in Larimer County, CO?
Larimer County is in Zone 5b with an average last frost of May 2. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Larimer County, CO?
Larimer County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 6.
When should I plant Arugula in Larimer County, CO?
In Larimer County, CO, plant Arugula after the last frost (around May 2) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Larimer County, CO for Arugula?
Larimer County sits in USDA Zone 5b. Arugula grows reliably in zones 3a through 11b, so it's a good fit here.
Can Arugula grow in Larimer County's climate?
Yes — Arugula grows well in Larimer County's temperate climate. Larimer County averages a 157-day frost-free season, with last frost around May 2 and first frost around October 6.
Your Larimer County Garden Planner — Free
A 22-page printable planner built for Larimer 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.