When to Plant Shiso in Grant County, NM
Your May planting checklist for Grant County, New Mexico
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Plant out shiso
Your last frost (April 27) has passed. These warm-season crops can handle outdoor soil now.
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Sow shiso where they'll grow
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
Coming up in June — start thinking about
- Starting indoors: 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.
Grant County, New Mexico is in USDA Zone 7b. The average last spring frost is April 27 and the first fall frost is October 22, giving you a growing season of approximately 178 days.
At an elevation of 3,721 feet, Grant County receives approximately 15.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°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. With low rainfall, drip irrigation is essential for growing Shiso successfully. Mulch heavily to conserve soil moisture.
Grant County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.9-8.2
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 Grant County
How your county's soil matches Shiso's growing requirements.
Soil pH
Your soil pH (6.9–8.2) is more alkaline than Shiso prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Grant 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 (0.8%). Add 2-3 inches of compost before planting Shiso.
How to Plant Shiso
Succession Planting Shiso
Sow every 5.7 weeks. Last sowing by Aug 13 to harvest before frost.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
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" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| May | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jun | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Jul | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Aug | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Sep | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Oct | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Nov | — | 0.9" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Grant 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 — Grant County, NM
Shiso Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 9 | Mar 9 – Mar 23 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | May 4 | May 4 – May 25 |
| Harvest | July 6 | Jul 6 – Aug 31 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| 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: too_alkaline
🗺️ USDA Zone
Zone 7b
📆 Growing Season
178 days in Grant County
Growing Tips for Shiso in Grant County
Direct sow Shiso outdoors after April 27 in Grant County when soil has warmed and frost danger has passed.
Sandy soil in Grant County dries quickly — mulch Shiso with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Grant County receives only 16" of rain annually. Shiso needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Grant County, NM?
Grant County is in Zone 7b with an average last frost of April 27. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grant County, NM?
Grant County, New Mexico is in USDA Hardiness Zone 7b. The average last spring frost is April 27 and first fall frost is October 22.
Your Grant County Garden Planner — Free
A 24-page printable planner built for Grant County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.