When to plant Shiso in Grant County, MN
The best window to plant Shiso in Grant County, is May 8–May 29, when soil warms to 50°F. Last frost typically hits May 1; first frost October 7.
When to Plant Shiso in Grant County, MN
Your June planting checklist for Grant County, Minnesota
Each item below is timed to Grant County, Minnesota's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Start shiso indoors
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
A few tasks this June that'll pay off in July
- First harvests: shiso
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.
Grant County, Minnesota is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.
At an elevation of 1,371 feet, Grant County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Shiso to ensure they mature before fall.
Grant County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.8
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 Grant County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.1–6.8) is within Shiso's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Grant County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Shiso.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Jul 29 to harvest before frost.
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.8" | 0" | ❄️ Dormant |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Nov | — | 1.9" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Grant 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 — Grant County, MN
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 8 | May 8 – May 29 |
| Harvest | July 17 | Jul 17 – Sep 11 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 4b
📆 Growing Season
159 days in Grant County
Growing Tips for Shiso in Grant County
Direct sow Shiso outdoors after May 01 in Grant County when soil has warmed and frost danger has passed.
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 Grant County, MN?
Grant County is in Zone 4b with an average last frost of May 1. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grant County, MN?
Grant County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.
When should I plant Shiso in Grant County, MN?
In Grant County, MN, plant Shiso after the last frost (around May 1) and before the first frost (around October 7). Best results when soil holds above 50°F.
What growing zone is Grant County, MN for Shiso?
Grant County sits in USDA Zone 4b. Shiso grows reliably in zones 3a through 11b, so it's a good fit here.
Can Shiso grow in Grant County's climate?
Yes — Shiso grows well in Grant County's temperate climate. Grant County averages a 159-day frost-free season, with last frost around May 1 and first frost around October 7.
Your Grant County Garden Planner — Free
A 22-page printable planner built for Grant County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.