When to plant Shiso in Fowler, IL
Plant Shiso in Fowler, when soil hits 50°F — usually April 21. Continue planting through May 12 for the spring crop.
When to Plant Shiso in Fowler, IL
June in the garden — Adams County, Illinois
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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Start shiso under lights
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.
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Basket week: shiso
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
July will be here before you know it — start on
- 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.
Fowler, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 20, giving you a growing season of approximately 189 days.
At an elevation of 1,390 feet, Adams County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Shiso during the growing season.
Fowler Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.3
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 Fowler
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.2–7.3) overlaps with Shiso's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Adams 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 11 to harvest before frost.
Shiso 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3" | 1.3" | 💧 Light watering |
| May | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Adams 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 — Fowler, IL
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | June 23 | Jun 23 – Aug 18 |
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: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
189 days in Adams County
Growing Tips for Shiso in Fowler
Direct sow Shiso outdoors after April 14 in Adams 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
When should I plant Shiso in Fowler, IL?
In Fowler, IL, plant Shiso after the last frost (around April 14) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Fowler, IL for Shiso?
Fowler sits in USDA Zone 6a. Shiso grows reliably in zones 3a through 11b, so it's a good fit here.
Can Shiso grow in Fowler's climate?
Yes — Shiso grows well in Fowler's temperate climate. Fowler averages a 189-day frost-free season, with last frost around April 14 and first frost around October 20.
Your Adams County Garden Planner — Free
A 22-page printable planner built for Adams County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.