When to Plant Shiso in Thomas County, KS
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.
Thomas County, Kansas is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 12, giving you a growing season of approximately 165 days.
At an elevation of 810 feet, Thomas County receives approximately 26.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Shiso during the growing season.
Thomas County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.5
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 Thomas County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.8–7.5) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Thomas County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Shiso will thrive.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 03 to harvest before frost.
Plant 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 | — | 2.1" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| May | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Jun | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jul | 4.3" | 2.3" | 2" | 💧 Light watering |
| Aug | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Sep | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Oct | 4.3" | 2.3" | 2" | 💧 Light watering |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Thomas 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 — Thomas County, KS
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 12 | Mar 12 – Mar 26 |
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Direct Sow | May 7 | May 7 – May 28 |
| Harvest | July 9 | Jul 9 – Sep 3 |
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 | — |
| 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: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
165 days in Thomas County
Growing Tips for Shiso in Thomas County
Direct sow Shiso outdoors after April 30 in Thomas 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 Thomas County, KS?
Thomas County is in Zone 5b with an average last frost of April 30. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Thomas County, KS?
Thomas County, Kansas is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 12.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Thomas County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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