When to plant Shiso in Eagle County, CO
Eagle County's short 83-day growing season means one Shiso planting between June 23 and July 14. No fall crop in Zone 5b.
When to Plant Shiso in Eagle County, CO
Top priorities for Eagle 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 shiso from tray to bed
Your last frost (June 16) has passed. These warm-season crops can handle outdoor soil now.
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Seed shiso outdoors
Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.
Shiso (perilla) is a fragrant Japanese herb with large, ruffled leaves in green or purple varieties. It has a unique flavor combining mint, basil, and anise.
Eagle County, Colorado is in USDA Zone 5b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.
At an elevation of 7,116 feet, Eagle County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Shiso to ensure they mature before fall.
Eagle County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
Drainage
Well Drained
Shiso 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 Eagle County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.6–7.7) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Eagle County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Shiso.
How to Plant Shiso
Shiso Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Shiso
Shiso needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Shiso Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | — | 2.8" | 0" | ❄️ Dormant |
| May | — | 3.2" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Jul | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Aug | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Sep | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Oct | — | 2" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Eagle County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Shiso 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.
Shiso Planting Timeline — Eagle County, CO
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 28 | Apr 28 – May 12 |
| Transplant Outdoors | June 30 | Jun 30 – Jul 14 |
| Direct Sow | June 23 | Jun 23 – Jul 14 |
| Harvest | August 25 | Aug 25 – Oct 20 |
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
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
83 days in Eagle County
Growing Tips for Shiso in Eagle County
Direct sow Shiso outdoors after June 16 in Eagle County when soil has warmed and frost danger has passed.
Eagle County receives only 24" of rain annually. Shiso needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow after last frost or start indoors. Both green and red varieties are available. Pinch tips to encourage bushiness. Self-sows prolifically; deadhead to control.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Shiso in Other Locations
Frequently Asked Questions
When should I plant Shiso in Eagle County, CO?
Eagle County is in Zone 5b with an average last frost of June 16. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Eagle County, CO?
Eagle County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 16 and first fall frost is September 7.
When should I plant Shiso in Eagle County, CO?
In Eagle County, CO, plant Shiso after the last frost (around June 16) and before the first frost (around September 7). Best results when soil holds above 50°F.
What growing zone is Eagle County, CO for Shiso?
Eagle County sits in USDA Zone 5b. Shiso grows reliably in zones 3a through 11b, so it's a good fit here.
Can Shiso grow in Eagle County's climate?
Yes — Shiso grows well in Eagle County's temperate climate. Eagle County averages a 83-day frost-free season, with last frost around June 16 and first frost around September 7.
Your Eagle County Garden Planner — Free
A 22-page printable planner built for Eagle 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.