Blog

When to Plant Lemongrass in Douglas County, OR

Lemongrass is a tropical grass with a strong citrus aroma used extensively in Southeast Asian cuisine. The swollen stem bases are the most flavorful part.

Douglas County, Oregon is in USDA Zone 8a. The average last spring frost is April 4 and the first fall frost is November 5, giving you a growing season of approximately 215 days.

At an elevation of 377 feet, Douglas County receives approximately 52.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Lemongrass during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lemongrass root diseases.

Douglas County, OR (Zone 8a) Long season
215 days
Last Spring Frost April 4
215 growing days
First Fall Frost November 5

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🍅 Harvest: Jun 27 – Sep 26
Recommended (50%) ✓ Fits season (33 days to spare)
Start indoors: Feb 14 Transplant: Apr 18 🍅 Harvest: Jul 4 – Oct 3
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Mar 12 Transplant: May 14 🍅 Harvest: Jul 30 – Oct 29

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 Douglas County

How your county's soil matches Lemongrass's growing requirements.

Soil pH

Your soil pH (5.8โ€“6.4) is within Lemongrass's preferred range (5.5โ€“7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) โ€” Lemongrass will thrive.

How to Plant Lemongrass

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

Succession Planting Lemongrass

3
successive plantings in your 215-day season

Sow every 8.6 weeks. Last sowing by Jul 08 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 904 gal / 100 sq ft

Monthly Watering Guide for Lemongrass

Lemongrass needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Lemongrass Needs Rainfall You Supplement Action
Jan โ€” 8.6" 0" โ„๏ธ Dormant
Feb โ€” 6.2" 0" โ„๏ธ Dormant
Mar โ€” 4.9" 0" โ„๏ธ Dormant
Apr 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
May 6.5" 3.4" 3.1" ๐Ÿ’ง Light watering
Jun 6.5" 2.3" 4.2" ๐Ÿšฟ Regular watering
Jul 6.5" 0.8" 5.7" ๐Ÿšฟ Regular watering
Aug 6.5" 1" 5.5" ๐Ÿšฟ Regular watering
Sep 6.5" 2.2" 4.3" ๐Ÿšฟ Regular watering
Oct 6.5" 4" 2.5" ๐Ÿ’ง Light watering
Nov 6.5" 7.6" 0" โœ… Rainfall sufficient
Dec โ€” 7.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Douglas County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Lemongrass 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.

Lemongrass needs ~1,706 GDD — county provides 3,762 GDD Excellent fit

Lemongrass Planting Timeline โ€” Douglas County, OR

Lemongrass Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 โ€“ Feb 28
Transplant Outdoors April 18 Apr 18 โ€“ May 2
Direct Sow April 11 Apr 11 โ€“ May 2
Harvest July 4 Jul 4 โ€“ Oct 3

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

75โ€“120 days

๐Ÿงช Soil pH

Needs 5.5โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

215 days in Douglas County

Growing Tips for Lemongrass in Douglas County

Direct sow Lemongrass outdoors after April 04 in Douglas County when soil has warmed and frost danger has passed.

Common pests for Lemongrass in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

Start from divisions or store-bought stalks rooted in water. Grow in rich, moist soil with full sun. In cold climates, grow in containers and overwinter indoors.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemongrass in Douglas County, OR?

Douglas County is in Zone 8a with an average last frost of April 4. Plan your Lemongrass planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Douglas County, OR?

Douglas County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 4 and first fall frost is November 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Douglas County gardeners in Zone 8a 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 Douglas County, OR. Local conditions may vary. Last updated: April 2026.