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When to Plant Lemon Balm in Mariposa County, CA

Mariposa County, California Zone 7b April

Your April gardening checklist

Here's what deserves your attention in Mariposa County, California this month. Everything below is tailored to Zone 7b and timed around your local frost dates.

Avg. last frost April 18
Avg. first frost November 9
Soil temp (4") 58°F
Watering High
Pest pressure Moderate
Daylight 13 hrs
  1. Plant out lemon balm

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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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.

Mariposa County, California is in USDA Zone 7b. The average last spring frost is April 18 and the first fall frost is November 9, giving you a growing season of approximately 205 days.

At an elevation of 192 feet, Mariposa County receives approximately 19.2 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Lemon Balm during the growing season. With low rainfall, drip irrigation is essential for growing Lemon Balm successfully. Mulch heavily to conserve soil moisture.

Mariposa County, CA (Zone 7b) Long season
205 days
Last Spring Frost April 18
205 growing days
First Fall Frost November 9
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Mariposa 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 (101 days to spare)
Transplant: Mar 31 🍅 Harvest: Jun 2 – Jul 21
Recommended (50%) ✓ Fits season (86 days to spare)
Transplant: Apr 25 🍅 Harvest: Jun 27 – Aug 15
Safe Start (90%) ✓ Fits season (80 days to spare)
Transplant: May 25 🍅 Harvest: Jul 27 – Sep 14

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 Mariposa County

How your county's soil matches Lemon Balm's growing requirements.

Soil pH

Your soil pH (6.5–7.5) is within Lemon Balm's preferred range (5.5–7.5).

Soil Texture

The loam soil in Mariposa County is excellent for Lemon Balm — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Lemon Balm.

How to Plant Lemon Balm

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

Succession Planting Lemon Balm

4
successive plantings in your 205-day season

Sow every 6.9 weeks. Last sowing by Aug 31 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 233 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lemon Balm

Lemon Balm needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Lemon Balm Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 2.2" 1.6" 0.6" 💧 Light watering
May 2.2" 0.5" 1.7" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.2" 2" 🚿 Regular watering
Oct 2.2" 0.9" 1.3" 🚿 Regular watering
Nov 2.2" 1.9" 0.3" 💧 Light watering
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Mariposa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lemon Balm 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.

Lemon Balm needs ~1,186 GDD — county provides 3,741 GDD Excellent fit

Lemon Balm Planting Timeline — Mariposa County, CA

Lemon Balm Planting Calendar

Activity When Date Range
Transplant Outdoors April 25 Apr 25 – May 9
Harvest June 27 Jun 27 – Aug 15

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7b

📆 Growing Season

205 days in Mariposa County

Growing Tips for Lemon Balm in Mariposa County

Direct sow Lemon Balm outdoors after April 18 in Mariposa County when soil has warmed and frost danger has passed.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Mariposa County is in Zone 7b with an average last frost of April 18. Plan your Lemon Balm planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mariposa County, CA?

Mariposa County, California is in USDA Hardiness Zone 7b. The average last spring frost is April 18 and first fall frost is November 9.

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Your Mariposa County Garden Planner — Free

A 24-page printable planner built for Mariposa 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.

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

Sources & credits

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