Zone 3 · Herbs Growing Guide

When to Plant Lemongrass
in Zone 3

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 only — outdoors Jun 1 – Sep 1
Start indoors
Mar 15 – Apr 1
Last Frost
~May 15
Days to harvest
90–120 days
Difficulty
Easy
Wrong season — Zone 3
Harvest window: Jul – Sep

Planting Calendar

In Zone 3, Lemongrass should be planted outdoors Container only — outdoors Jun 1 – Sep 1, after the average last frost date of approximately May 15. Start seeds indoors around Mar 15 – Apr 1 for a head start.

Container only in Zone 3. Start indoors 8 weeks early. Move outside after last frost, bring in before first fall frost. One large pot per plant.

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 3

Container only in Zone 3. Start indoors 8 weeks early. Move outside after last frost, bring in before first fall frost. One large pot per plant.

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 3, start lemongrass seeds indoors around Mar 15 – Apr 1, then transplant outdoors Container only — outdoors Jun 1 – Sep 1 after your last frost around May 15. Container only in Zone 3. Start indoors 8 weeks early. Move outside after last frost, bring in before first fall frost. One large pot per plant.
Zone 3 has an average last spring frost of approximately May 15 and a first fall frost around Sep 15. 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 3. Expected harvest window: Jul – Sep.

Free app · iOS February 2028

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Lemongrass in other zones
Crop Guides