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When to Plant Lemongrass in Maricopa County, AZ

Maricopa County, Arizona Zone 9b May

What to do in May

Your Maricopa County, Arizona garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost January 31
Avg. first frost December 6
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs
  1. Pick lemongrass

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

June prep starts now
  • First harvests: lemongrass

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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.

Maricopa County, Arizona is in USDA Zone 9b. The average last spring frost is January 31 and the first fall frost is December 6, giving you a growing season of approximately 309 days.

At an elevation of 4,014 feet, Maricopa County receives approximately 12.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 108°F, so Lemongrass may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lemongrass will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Lemongrass successfully. Mulch heavily to conserve soil moisture.

Maricopa County, AZ (Zone 9b) Year-round
309 days
Last Spring Frost January 31
309 growing days
First Fall Frost December 6
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Maricopa County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (143 days to spare)
Start indoors: Dec 6 Transplant: Jan 24 🍅 Harvest: Apr 11 – Jul 11
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Dec 20 Transplant: Feb 7 🍅 Harvest: Apr 25 – Jul 25
Safe Start (90%) ✓ Fits season (129 days to spare)
Start indoors: Jan 16 Transplant: Mar 6 🍅 Harvest: May 22 – Aug 21

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 Maricopa County

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

Soil pH

Your soil pH (7.2–8.5) is more alkaline than Lemongrass prefers (5.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Maricopa County warms quickly in spring but drains fast. Lemongrass will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Lemongrass.

How to Plant Lemongrass

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

Succession Planting Lemongrass

4
successive plantings in your 309-day season

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

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.2″/week
You supply
1.6″/week
Watering frequency 2-3 times/week
Season total 4,405 gal / 100 sq ft
Drought risk

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

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 6.5" 0.9" 5.6" 🚿 Regular watering
Feb 6.5" 0.8" 5.7" 🚿 Regular watering
Mar 6.5" 0.7" 5.8" 🚿 Regular watering
Apr 6.5" 0.5" 6" 🚿 Regular watering
May 6.5" 0.3" 6.2" 🚿 Regular watering
Jun 6.5" 0.4" 6.1" 🚿 Regular watering
Jul 6.5" 2.1" 4.4" 🚿 Regular watering
Aug 6.5" 2.3" 4.2" 🚿 Regular watering
Sep 6.5" 1.9" 4.6" 🚿 Regular watering
Oct 6.5" 1.2" 5.3" 🚿 Regular watering
Nov 6.5" 0.6" 5.9" 🚿 Regular watering
Dec 6.5" 0.8" 5.7" 🚿 Regular watering

Water needs are for active growing months only (Jan–Dec in Maricopa County). Supplement amounts are based on average rainfall — 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" — 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.

Lemongrass needs ~3,022 GDD — county provides 9,610 GDD Excellent fit

Lemongrass Planting Timeline — Maricopa County, AZ

Lemongrass Planting Calendar

Activity When Date Range
Start Indoors December 20 Dec 20 – Jan 3
Transplant Outdoors February 7 Feb 7 – Feb 21
Direct Sow February 7 Feb 7 – Feb 28
Harvest April 25 Apr 25 – Jul 25

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

75–120 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

309 days in Maricopa County

Growing Tips for Lemongrass in Maricopa County

Direct sow Lemongrass outdoors after January 31 in Maricopa County when soil has warmed and frost danger has passed.

Sandy soil in Maricopa County dries quickly — mulch Lemongrass with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 108°F in Maricopa County, provide afternoon shade for Lemongrass and water deeply in the morning.

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

Maricopa County receives only 12" of rain annually. Lemongrass needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Maricopa County, AZ?

Maricopa County is in Zone 9b with an average last frost of January 31. Plan your Lemongrass planting based on this frost date — see the calendar above for exact timing.

What planting zone is Maricopa County, AZ?

Maricopa County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is January 31 and first fall frost is December 6.

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Your Maricopa County Garden Planner — Free

A 24-page printable planner built for Maricopa County (Zone 9b). 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 Maricopa County, AZ. Local conditions may vary. Last updated: May 2026.

Sources & credits

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