When to Plant Shiso in Monroe County, FL
Your May planting checklist for Monroe County, Florida
A quick May briefing for Monroe County, Florida gardeners — what's urgent, what's next, and what can wait.
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Start harvesting shiso
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
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.
Monroe County, Florida is in USDA Zone 11b. The average last spring frost is January 22 and the first fall frost is April 15, giving you a growing season of approximately 83 days.
At an elevation of 169 feet, Monroe County receives approximately 55.6 inches of rainfall annually with predominantly sand soil. Summer highs average 93°F, providing good warmth for Shiso during the growing season. Sandy soil warms quickly in spring — great for early planting — but Shiso will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.
Monroe County Soil Profile
Soil Type
Sand
Soil pH
4.8-5.7
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 Monroe County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (4.8–5.7) is more acidic than Shiso prefers (5.5–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Monroe County warms quickly in spring but drains fast. Shiso will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Shiso.
Organic Matter
Organic matter is low (1.3%). Add 2-3 inches of compost before planting Shiso.
How to Plant Shiso
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 | 4.3" | 2.3" | 2" | 💧 Light watering |
| Feb | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Mar | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Apr | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| May | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Jun | 4.3" | 7.1" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 8.2" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.7" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 7.7" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jan–Oct in Monroe 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 — Monroe County, FL
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 11 | Dec 11 – Dec 25 |
| Transplant Outdoors | January 29 | Jan 29 – Feb 12 |
| Direct Sow | January 29 | Jan 29 – Feb 19 |
| Harvest | March 26 | Mar 26 – May 21 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
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_acidic
🗺️ USDA Zone
Zone 11b
📆 Growing Season
83 days in Monroe County
Growing Tips for Shiso in Monroe County
Direct sow Shiso outdoors after January 22 in Monroe County when soil has warmed and frost danger has passed.
Sandy soil in Monroe County dries quickly — mulch Shiso with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
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 Monroe County, FL?
Monroe County is in Zone 11b with an average last frost of January 22. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Monroe County, FL?
Monroe County, Florida is in USDA Hardiness Zone 11b. The average last spring frost is January 22 and first fall frost is .
Your Monroe County Garden Planner — Free
A 24-page printable planner built for Monroe County (Zone 11b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.