When to Plant Shiso in Ransom County, ND
Your May gardening checklist
May is a pivotal month for Ransom County, North Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Plant out shiso
Frost risk is low now in Ransom County, North Dakota. If you've been covering beds overnight, you can stop.
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Scatter shiso into prepared beds
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
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.
Ransom County, North Dakota is in USDA Zone 4a. The average last spring frost is May 8 and the first fall frost is October 3, giving you a growing season of approximately 148 days.
At an elevation of 517 feet, Ransom County receives approximately 32.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Shiso to ensure they mature before fall.
Ransom County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.3
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 Ransom County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.7–7.3) overlaps with Shiso's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Ransom County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.4%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Jul 25 to harvest before frost.
Plant Water Budget
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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 3.7" | 0" | ❄️ Dormant |
| May | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Oct | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Nov | — | 1.1" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Ransom 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 — Ransom County, ND
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | May 29 | May 29 – Jun 12 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Harvest | July 24 | Jul 24 – Sep 18 |
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 Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 4a
📆 Growing Season
148 days in Ransom County
Growing Tips for Shiso in Ransom County
Direct sow Shiso outdoors after May 08 in Ransom 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 Ransom County, ND?
Ransom County is in Zone 4a with an average last frost of May 8. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ransom County, ND?
Ransom County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 8 and first fall frost is October 3.
Your Ransom County Garden Planner — Free
A 24-page printable planner built for Ransom County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.