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When to Plant Lemon Balm in Fresno County, CA

Lemon balm is a vigorous perennial herb with bright green, lemon-scented leaves. It makes a refreshing tea and is easy to grow but can spread aggressively.

Fresno County, California is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 23, giving you a growing season of approximately 266 days.

At an elevation of 2,276 feet, Fresno County receives approximately 14.9 inches of rainfall annually with predominantly loam soil. Summer highs average 100ยฐF, so Lemon Balm may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Lemon Balm successfully. Mulch heavily to conserve soil moisture.

Fresno County, CA (Zone 9a) Long season
266 days
Last Spring Frost March 2
266 growing days
First Fall Frost November 23

Fresno County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (148 days to spare)
Transplant: Feb 23 🍅 Harvest: Apr 27 – Jun 15
Recommended (50%) ✓ Fits season (147 days to spare)
Transplant: Mar 9 🍅 Harvest: May 11 – Jun 29
Safe Start (90%) ✓ Fits season (99 days to spare)
Transplant: May 18 🍅 Harvest: Jul 20 – Sep 7

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,173 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Lemon Balm needs ~1,625 GDD — county provides 6,650 GDD Excellent fit

Lemon Balm Planting Timeline โ€” Fresno County, CA

Lemon Balm Planting Calendar

Activity When Date Range
Transplant Outdoors March 9 Mar 9 โ€“ Mar 23
Harvest May 11 May 11 โ€“ Jun 29

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“70 days

Soil pH

5.5 โ€“ 7.5

USDA Zone

Zone 9a

Growing Season

266 days

Growing Tips for Fresno County

Start from seed, cuttings, or divisions. Contain in pots or use barriers to prevent spreading. Harvest frequently to keep plants bushy and prevent flowering.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Lemon Balm in Fresno County, CA?

Fresno County is in Zone 9a with an average last frost of March 2. Plan your Lemon Balm planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Fresno County, CA?

Fresno County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 23.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Fresno County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Fresno County, CA. Local conditions may vary. Last updated: April 2026.