When to Plant Shiso in Union Parish, LA
May in the garden — Union Parish, Louisiana
Here's what deserves your attention in Union Parish, Louisiana this month. Everything below is tailored to Zone 8b and timed around your local frost dates.
-
Fire up the seed-starting tray: shiso
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
-
Basket week: shiso
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
A few tasks this May that'll pay off in June
- 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.
Union Parish, Louisiana is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 5, giving you a growing season of approximately 228 days.
At an elevation of 426 feet, Union Parish receives approximately 57.4 inches of rainfall annually with predominantly loam soil. Summer highs average 96°F, so Shiso may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Shiso root diseases.
Union Parish Soil Profile
Soil Type
Loam
Soil pH
5.9-7
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 Union Parish
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (5.9–7.0) is within Shiso's preferred range (5.5–7.0).
Soil Texture
The loam soil in Union Parish is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 27 to harvest before frost.
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 | — | 4.6" | 0" | ❄️ Dormant |
| Feb | — | 4.7" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| May | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Union Parish). 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 — Union Parish, LA
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 1 | Feb 1 – Feb 15 |
| Transplant Outdoors | April 5 | Apr 5 – Apr 19 |
| Direct Sow | March 29 | Mar 29 – Apr 19 |
| Harvest | May 31 | May 31 – Jul 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 8b
📆 Growing Season
228 days in Union Parish
Growing Tips for Shiso in Union Parish
Direct sow Shiso outdoors after March 22 in Union Parish when soil has warmed and frost danger has passed.
With summer highs reaching 96°F in Union Parish, provide afternoon shade for Shiso and water deeply in the morning.
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 Union Parish, LA?
Union Parish is in Zone 8b with an average last frost of March 22. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union Parish, LA?
Union Parish, Louisiana is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 5.
Your Union Parish Garden Planner — Free
A 24-page printable planner built for Union Parish (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.