When to Plant Leeks

Leeks are a hardy cool-season vegetable. They can take a hard frost.

Start seeds indoors 10 to 12 weeks before the last spring frost, and plant out 1 to 4 weeks before the last frost. The first harvest comes about 80 to 110 days after transplanting.

Example dates

The same rules in dates for three climates, using typical frost dates. Enter your ZIP code above for the dates where you live.

Leeks: dates by last spring and first fall frost
TaskLast frost Mar 15first Nov 15Last frost Apr 15first Oct 25Last frost May 15first Sep 30
Start seeds indoorsDec 21 – Jan 4Jan 21 – Feb 4Feb 20 – Mar 6
Harden offFeb 8 – 14Mar 11 – 17Apr 10 – 16
Plant outFeb 15 – Mar 8Mar 18 – Apr 8Apr 17 – May 8
HarvestMay 6 – Jul 1Jun 6 – Aug 1Jul 6 – Aug 31

Growing leeks

Hill soil or mulch around the stems as they grow to lengthen the white shank.

Plan your beds with these dates

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Questions

When do I start leeks indoors?

10 to 12 weeks before the last spring frost: with a last frost of April 15, that's Jan 21 – Feb 4. Enter your ZIP code above for your own dates.

Can leeks go in before the last frost?

Yes. Leeks are hardy: plant them out 1 to 4 weeks before the last spring frost.

How long do leeks take to grow?

About 80 to 110 days from transplanting to the first harvest, which then lasts about 8 weeks. Varieties differ: check the seed packet.

More planting dates

Sources

  1. NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020 (annual/seasonal, by station: freeze dates at 32 °F)
  2. Colorado State University Extension: Vegetable Planting Guide (CMG GardenNotes #720)
  3. Virginia Cooperative Extension, Virginia Tech: Virginia's Home Garden Vegetable Planting Guide: Recommended Planting Dates and Amounts to Plant (426-331 / SPES-673P, 2025)
  4. University of Maryland Extension: Vegetable Planting Calendar for central Maryland
  5. UNH Cooperative Extension: Growing Vegetables: When to Plant your Vegetable Garden (2016)
  6. NC State Extension: Extension Gardener Handbook, Chapter 16: Vegetable Gardening
  7. WSU Extension: Pacific Northwest Gardener's Handbook, Chapter 7: Vegetable Gardening
  8. Iowa State University Extension and Outreach: Vegetable Planting and Harvesting Times (chart, central Iowa)
  9. Iowa State: The Other Onions
  10. Cornell Cooperative Extension, Rockland County: Vegetable Planting Guide (Hort 52)
  11. Clemson Cooperative Extension HGIC: Small-Scale Gardening (square-foot planting guide)
  12. UC Master Gardener Program, UC ANR: Companion Planting Chart: Companion Planting for Edible Crops
  13. SDSU Extension: Square-Foot Garden Sample Planting Layout (P-00379, 2026)
  14. University of Arizona Cooperative Extension, Yavapai County: The Art of Companion Planting (Master Gardener presentation, 2023)