When to plant Shiso in Hamilton County, IL
In Hamilton County, plant Shiso in spring between April 16 and May 7, once soil temps hold above 50°F. Hamilton County's last frost averages April 9, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 50–70 days before the first frost on October 23.
When to Plant Shiso in Hamilton County, IL
Your June gardening checklist
We've pulled the most time-sensitive tasks for Hamilton County, Illinois this June and put them front and centre. Tackle them in order.
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Collect shiso at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
To set up a strong July, finish these tasks
- 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.
Hamilton County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 23, giving you a growing season of approximately 197 days.
At an elevation of 524 feet, Hamilton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Shiso during the growing season.
Hamilton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.7
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 Hamilton County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (5.8–6.7) is within Shiso's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Hamilton County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Shiso will thrive.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 14 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Hamilton 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 — Hamilton County, IL
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 19 | Feb 19 – Mar 5 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 16 | Apr 16 – May 7 |
| Harvest | June 18 | Jun 18 – Aug 13 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| 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: ideal
🗺️ USDA Zone
Zone 6b
📆 Growing Season
197 days in Hamilton County
Growing Tips for Shiso in Hamilton County
Direct sow Shiso outdoors after April 09 in Hamilton 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 Hamilton County, IL?
Hamilton County is in Zone 6b with an average last frost of April 9. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hamilton County, IL?
Hamilton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 23.
When should I plant Shiso in Hamilton County, IL?
In Hamilton County, IL, plant Shiso after the last frost (around April 9) and before the first frost (around October 23). Best results when soil holds above 50°F.
What growing zone is Hamilton County, IL for Shiso?
Hamilton County sits in USDA Zone 6b. Shiso grows reliably in zones 3a through 11b, so it's a good fit here.
Can Shiso grow in Hamilton County's climate?
Yes — Shiso grows well in Hamilton County's temperate climate. Hamilton County averages a 197-day frost-free season, with last frost around April 9 and first frost around October 23.
Your Hamilton County Garden Planner — Free
A 22-page printable planner built for Hamilton County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.