When to Plant Mint in Costilla County, CO
May in the garden — Costilla County, Colorado
We've pulled the most time-sensitive tasks for Costilla County, Colorado this May and put them front and centre. Tackle them in order.
June will be here before you know it — start on
- 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.
Costilla County, Colorado is in USDA Zone 5b. The average last spring frost is June 8 and the first fall frost is September 16, giving you a growing season of approximately 100 days.
At an elevation of 5,598 feet, Costilla County receives approximately 21 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Mint during the growing season.
Costilla County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.3
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 Costilla County
How your county's soil matches Mint's growing requirements.
Soil pH
Your soil pH (6.2–8.3) is more alkaline than Mint prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Costilla County is excellent for Mint — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Mint is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is moderate (2.5%). 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | — | 2.5" | 0" | ❄️ Dormant |
| Jun | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Jul | 3" | 2" | 1" | 💧 Light watering |
| Aug | 3" | 2.5" | 0.5" | 💧 Light watering |
| Sep | 3" | 1.7" | 1.3" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Costilla 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 — Costilla County, CO
Mint Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 15 | Jun 15 – Jun 29 |
| Harvest | August 17 | Aug 17 – Oct 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
100 days in Costilla County
Growing Tips for Mint in Costilla County
Direct sow Mint outdoors after June 08 in Costilla County when soil has warmed and frost danger has passed.
Your 100.0-day growing season in Costilla 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 Costilla County, CO?
Costilla County is in Zone 5b with an average last frost of June 8. Plan your Mint planting based on this frost date — see the calendar above for exact timing.
What planting zone is Costilla County, CO?
Costilla County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 8 and first fall frost is September 16.
Your Costilla County Garden Planner — Free
A 24-page printable planner built for Costilla 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.