When to Plant Shiso in Hunterdon County, NJ
May in Hunterdon County, New Jersey — your action list
Your Hunterdon County, New Jersey garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Start shiso under lights
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
June 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.
Hunterdon County, New Jersey is in USDA Zone 7a. The average last spring frost is April 12 and the first fall frost is October 29, giving you a growing season of approximately 200 days.
At an elevation of 534 feet, Hunterdon County receives approximately 46.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Shiso during the growing season.
Hunterdon County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.3
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 Hunterdon County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (5.2–6.3) overlaps with Shiso's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Hunterdon County is excellent for Shiso — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.7%). Annual compost additions will help Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 20 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 | — | 3.7" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 4.1" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Oct | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 3.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Hunterdon 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 — Hunterdon County, NJ
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 22 | Feb 22 – Mar 8 |
| Transplant Outdoors | April 26 | Apr 26 – May 10 |
| Direct Sow | April 19 | Apr 19 – May 10 |
| Harvest | June 21 | Jun 21 – Aug 16 |
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 7a
📆 Growing Season
200 days in Hunterdon County
Growing Tips for Shiso in Hunterdon County
Direct sow Shiso outdoors after April 12 in Hunterdon 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 Hunterdon County, NJ?
Hunterdon County is in Zone 7a with an average last frost of April 12. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hunterdon County, NJ?
Hunterdon County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is April 12 and first fall frost is October 29.
Your Hunterdon County Garden Planner — Free
A 24-page printable planner built for Hunterdon County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.