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When to Plant Lemon Balm in Coos County, OR

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.

Coos County, Oregon is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Lemon Balm during the growing season.

Coos County, OR (Zone 8b) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (120 days to spare)
Transplant: Mar 14 🍅 Harvest: May 16 – Jul 4
Recommended (50%) ✓ Fits season (123 days to spare)
Transplant: Mar 29 🍅 Harvest: May 31 – Jul 19
Safe Start (90%) ✓ Fits season (118 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 19

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 Coos County

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

Soil pH

Your soil pH (5.4โ€“6.8) overlaps with Lemon Balm's range (5.5โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in Coos County is excellent for Lemon Balm โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) โ€” Lemon Balm will thrive.

How to Plant Lemon Balm

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

Succession Planting Lemon Balm

4
successive plantings in your 242-day season

Sow every 6.9 weeks. Last sowing by Sep 10 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 โ€” 5.5" 0" โ„๏ธ Dormant
Feb โ€” 4.5" 0" โ„๏ธ Dormant
Mar 2.2" 4.4" 0" โœ… Rainfall sufficient
Apr 2.2" 3.1" 0" โœ… Rainfall sufficient
May 2.2" 2.3" 0" โœ… Rainfall sufficient
Jun 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Jul 2.2" 0.6" 1.6" ๐Ÿšฟ Regular watering
Aug 2.2" 0.8" 1.4" ๐Ÿšฟ Regular watering
Sep 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Oct 2.2" 3.3" 0" โœ… Rainfall sufficient
Nov 2.2" 5.9" 0" โœ… Rainfall sufficient
Dec โ€” 5.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Coos County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,089 GDD — county provides 4,053 GDD Excellent fit

Lemon Balm Planting Timeline โ€” Coos County, OR

Lemon Balm Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 โ€“ Apr 12
Harvest May 31 May 31 โ€“ Jul 19

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“70 days

๐Ÿงช Soil pH

Needs 5.5โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

242 days in Coos County

Growing Tips for Lemon Balm in Coos County

Direct sow Lemon Balm outdoors after March 22 in Coos 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 Coos County, OR?

Coos County is in Zone 8b with an average last frost of March 22. Plan your Lemon Balm planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Coos County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Coos County, OR. Local conditions may vary. Last updated: April 2026.