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When to Plant Shiso in Palm Beach County, FL

Palm Beach County, Florida Zone 10b May

Palm Beach County, Florida gardeners: here's your May plan

Each item below is timed to Palm Beach County, Florida's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 17
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 13.3 hrs
  1. Bring in the shiso

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Before June arrives, get these ready
  • First harvests: shiso

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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.

Palm Beach County, Florida is in USDA Zone 10b. The average last spring frost is February 17 and the first fall frost is April 15, giving you a growing season of approximately 57 days.

At an elevation of 355 feet, Palm Beach County receives approximately 50 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.

Palm Beach County, FL (Zone 10b) Very short season
57 days
Last Spring Frost February 17
57 growing days
First Fall Frost April 15

Palm Beach County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (128 days to spare)
Start indoors: Dec 30 Transplant: Feb 17 🍅 Harvest: Apr 14 – Jun 9
Recommended (50%) ✓ Fits season (121 days to spare)
Start indoors: Jan 6 Transplant: Feb 24 🍅 Harvest: Apr 21 – Jun 16
Safe Start (90%) ✓ Fits season (114 days to spare)
Start indoors: Jan 13 Transplant: Mar 3 🍅 Harvest: Apr 28 – Jun 23

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 Palm Beach County

How your county's soil matches Shiso's growing requirements.

Soil pH

Your soil pH (5.1–5.9) overlaps with Shiso's range (5.5–7.0), though not a perfect match.

Soil Texture

Sandy soil in Palm Beach 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

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 2,354 gal / 100 sq ft

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 2.4" 0" ❄️ Dormant
Feb 4.3" 2.3" 2" 💧 Light watering
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 6.2" 0" ✅ Rainfall sufficient
Jul 4.3" 7.3" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Oct in Palm Beach 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 needs ~1,185 GDD — county provides 7,208 GDD Excellent fit

Shiso Planting Timeline — Palm Beach County, FL

Shiso Planting Calendar

Activity When Date Range
Start Indoors January 6 Jan 6 – Jan 20
Transplant Outdoors February 24 Feb 24 – Mar 10
Direct Sow February 24 Feb 24 – Mar 17
Harvest April 21 Apr 21 – Jun 16

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Harvest
May Harvest
June Harvest
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10b

📆 Growing Season

57 days in Palm Beach County

Growing Tips for Shiso in Palm Beach County

Direct sow Shiso outdoors after February 17 in Palm Beach County when soil has warmed and frost danger has passed.

Sandy soil in Palm Beach 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 →

Frequently Asked Questions

When should I plant Shiso in Palm Beach County, FL?

Palm Beach County is in Zone 10b with an average last frost of February 17. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Palm Beach County, FL?

Palm Beach County, Florida is in USDA Hardiness Zone 10b. The average last spring frost is February 17 and first fall frost is .

🌱

Your Palm Beach County Garden Planner — Free

A 24-page printable planner built for Palm Beach County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Palm Beach County, FL. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.