Zone 4 · Herbs Growing Guide

When to Plant Lemongrass
in Zone 4

A tropical grass that doubles as a dramatic ornamental clump. Harvest stalks for curries, soups, and teas. In warm zones it's a large perennial — in cold zones, grow in a pot and bring indoors in winter.

Plant outdoors
Container — outdoors May 20 – Sep 20
Start indoors
Mar 20 – Apr 5
Last Frost
~May 1
Days to harvest
90–120 days
Difficulty
Easy
Wrong season — Zone 4
Harvest window: Jun – Sep

Planting Calendar

In Zone 4, Lemongrass should be planted outdoors Container — outdoors May 20 – Sep 20, after the average last frost date of approximately May 1. Start seeds indoors around Mar 20 – Apr 5 for a head start.

Container growing. Move outdoors once nights stay above 50°F. Bring in before first frost.

Care Guide

Sunlight
Full sun · 6–8 hrs/day
Watering
Moderate
Spacing
24–36 inches
Soil
Well-draining, fertile, moisture-retentive
Days to maturity
90–120 days
Soil pH
5.5–7.0
plant tip · Zone 4

Container growing. Move outdoors once nights stay above 50°F. Bring in before first frost.

Feeding Schedule

How often
monthly
Feed type
high nitrogen
Key timing
throughout growing season

Tropical grass that loves nitrogen. Feed monthly during the growing season. Reduce feeding in autumn.

Companion Planting for Lemongrass

What you plant next to lemongrass makes a real difference — some plants actively help, others compete or attract pests.

Grows well with
  • Basil
  • Mint
  • Tomatoes
  • Peppers
Keep away from
  • Fennel

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Common questions

In Zone 4, start lemongrass seeds indoors around Mar 20 – Apr 5, then transplant outdoors Container — outdoors May 20 – Sep 20 after your last frost around May 1. Container growing. Move outdoors once nights stay above 50°F. Bring in before first frost.
Zone 4 has an average last spring frost of approximately May 1 and a first fall frost around Oct 1. These dates vary by specific location — use your ZIP code in the plant app for precision based on the nearest NOAA weather station.
Good companion crops for lemongrass include Basil, Mint, Tomatoes, Peppers. Avoid planting near Fennel, which can compete for nutrients or attract pests.
Lemongrass typically takes 90–120 days from transplant or direct sow to harvest in Zone 4. Expected harvest window: Jun – Sep.

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Lemongrass in other zones
Crop Guides