When to Plant Mint in Lake County, CO
May in the garden — Lake County, Colorado
Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.
Looking ahead to June
- Transplants going out: mint
Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.
Lake County, Colorado is in USDA Zone 5a. The average last spring frost is June 21 and the first fall frost is August 30, giving you a growing season of approximately 70 days.
At an elevation of 7,687 feet, Lake County receives approximately 21.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Mint to ensure they mature before fall.
Lake County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.2
Drainage
Well Drained
Plant 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 Lake County
How your county's soil matches Mint's growing requirements.
Soil pH
Your soil pH (6.6–8.2) is more alkaline than Mint prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Lake County is excellent for Mint — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Mint.
How to Plant Mint
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Mint
Mint needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Mint Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | — | 2.7" | 0" | ❄️ Dormant |
| Jun | 3" | 1.4" | 1.6" | 🚿 Regular watering |
| Jul | 3" | 2.1" | 0.9" | 💧 Light watering |
| Aug | 3" | 2.2" | 0.8" | 💧 Light watering |
| Sep | — | 1.6" | 0" | ❄️ Dormant |
| Oct | — | 2.1" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Aug in Lake County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mint 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.
Mint Planting Timeline — Lake County, CO
Mint Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 28 | Jun 28 – Jul 12 |
| Harvest | August 30 | Aug 30 – Nov 8 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
70 days in Lake County
Growing Tips for Mint in Lake County
Direct sow Mint outdoors after June 21 in Lake County when soil has warmed and frost danger has passed.
Your 70.0-day growing season in Lake County is tight for Mint (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mint in Other Locations
Frequently Asked Questions
When should I plant Mint in Lake County, CO?
Lake County is in Zone 5a with an average last frost of June 21. Plan your Mint planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lake County, CO?
Lake County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 21 and first fall frost is August 30.
Your Lake County Garden Planner — Free
A 24-page printable planner built for Lake 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.