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When to Plant Onion in USDA Zone 7a

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

In Zone 7a, the average last spring frost is around March 25 and the first fall frost is around November 1, giving you a growing season of approximately 221 days.

Zone 7a Long season
221 days
Last Spring Frost March 25
221 growing days
First Fall Frost November 1

Onion Planting Timeline — Zone 7a

Where Is USDA Zone 7a?

The map below highlights the states that contain Zone 7a. Click any state to see the Onion planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Onion Planting Calendar — Zone 7a

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 11 Mar 11 – Apr 1
Harvest June 24 Jun 24 – Aug 12
Fall Sowing August 23 Aug 23 – Sep 6

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Free Zone 7a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 7a with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

90–120 days

Soil pH

6 – 7

Zone Temperature Range

0°F to 5°F average annual minimum

Growing Season

221 days (Zone 7a average)

Planting Specifications

Planting Depth1 inches
Plant Spacing6 inches apart
Row Spacing12 inches between rows

Growing Tips for Onion in Zone 7a

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Level Up Your Garden

Saving Onion Seeds

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Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

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Frequently Asked Questions

When should I plant Onion in Zone 7a?

In Zone 7a, plan your Onion planting around the average last frost date of March 25. Start seeds indoors around February 18. Direct sow outdoors around March 11. Transplant seedlings around March 25.

Can Onion grow in Zone 7a?

Yes, Onion can grow well in Zone 7a, hardy in USDA zones 3a through 10b. Zone 7a has a growing season of approximately 221 days, which is sufficient for Onion (90-120 days to maturity).

When can I harvest Onion in Zone 7a?

In Zone 7a, expect to harvest Onion from June 24 – August 12. Onion takes 90-120 days from planting to harvest.

What is the last frost date for Zone 7a?

The average last spring frost in Zone 7a is around March 25, and the first fall frost is around November 1. This gives a growing season of approximately 221 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Onion?

Good companion plants for Onion include Carrots, Lettuce, Beets, Cabbage. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 7a, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.