When to plant Basil in Routt County County,
Routt County County sits in cold Zone 5a. Plant Basil June 19–July 10 for the single annual harvest; the September 8 first frost closes the window.
When to Plant Basil in Routt County, CO
Top priorities for Routt County, Colorado gardeners in June
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Move basil into the garden
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Direct-sow basil
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Before July arrives, get these ready
- Starting indoors: basil
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
Routt County, Colorado is in USDA Zone 5a. The average last spring frost is June 12 and the first fall frost is September 8, giving you a growing season of approximately 88 days.
At an elevation of 5,381 feet, Routt County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Basil to ensure they mature before fall.
Routt County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.9
Drainage
Well Drained
Basil 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 Routt County
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (6.7–7.9) is more alkaline than Basil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Routt County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Basil.
How to Plant Basil
Basil Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Basil
Basil 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 | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 2.7" | 0" | ❄️ Dormant |
| May | — | 2.8" | 0" | ❄️ Dormant |
| Jun | 2.6" | 1.5" | 1.1" | 💧 Light watering |
| Jul | 2.6" | 2.2" | 0.4" | 💧 Light watering |
| Aug | 2.6" | 2.2" | 0.4" | 💧 Light watering |
| Sep | 2.6" | 2.3" | 0.3" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.5" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Routt County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Basil 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.
Basil Planting Timeline — Routt County, CO
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 24 | Apr 24 – May 8 |
| Transplant Outdoors | June 26 | Jun 26 – Jul 10 |
| Direct Sow | June 19 | Jun 19 – Jul 10 |
| Harvest | August 21 | Aug 21 – Oct 23 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow |
| July | Transplant Outdoors Direct Sow |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
88 days in Routt County
Growing Tips for Basil in Routt County
Direct sow Basil outdoors after June 12 in Routt County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Routt County, CO?
Routt County is in Zone 5a with an average last frost of June 12. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Routt County, CO?
Routt County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 12 and first fall frost is September 8.
When should I plant Basil in Routt County, ?
In Routt County, , plant Basil after the last frost (around June 12) and before the first frost (around September 8). Best results when soil holds above 50°F.
What growing zone is Routt County, for Basil?
Routt County sits in USDA Zone 5a. Basil grows reliably in zones 4a through 11b, so it's a good fit here.
Can Basil grow in Routt County's climate?
Yes — Basil grows well in Routt County's temperate climate. Routt County averages a 88-day frost-free season, with last frost around June 12 and first frost around September 8.
Your Routt County Garden Planner — Free
A 22-page printable planner built for Routt County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.