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When to Plant Lettuce in USDA Zone 4a

Lettuce
Zone 4a Zone 4a June

June to-do list for Zone 4a

Each item below is timed to Zone 4a's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 13
Avg. first frost September 28
  1. Start lettuce under lights

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Start harvesting lettuce

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

July will be here before you know it — start on
  • First harvests: lettuce
  • Fall sowing: lettuce
Get the full Zone 4a Garden Planner — free →
Lettuce

Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.

In Zone 4a, the average last spring frost is around May 6 and the first fall frost is around September 28, giving you a growing season of approximately 145 days.

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Zone 4a Short season
145 days
Last Spring Frost May 6
145 growing days
First Fall Frost September 28

Lettuce Planting Timeline — Zone 4a

Where Is USDA Zone 4a?

The map below highlights the states that contain Zone 4a. Click any state to see the Lettuce planting schedule for that location.

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

Lettuce Planting Calendar — Zone 4a

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 29 Apr 29 – May 20
Harvest June 10 Jun 10 – Aug 19
Fall Sowing July 6 Jul 6 – Jul 20

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Free Zone 4a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4a with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Moderate — regular watering

Days to Maturity

30–60 days

Soil pH

6 – 7

Zone Temperature Range

-30°F to -25°F average annual minimum

Growing Season

145 days (Zone 4a average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing6 inches apart
Row Spacing12 inches between rows

Succession Planting Lettuce in Zone 4a

5
successive plantings in Zone 4a's ~145-day season

Sow every 3.4 weeks for continuous harvest throughout the season.

Growing Tips for Lettuce in Zone 4a

Zone 4a has a short growing season (~145 days). Start Lettuce indoors early and use season-extension techniques like row covers and cold frames.

Lettuce needs approximately 0.7 inches of water per week during active growth. Adjust watering based on your local rainfall and soil drainage.

Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.

Companion Planting

Good Companions

Avoid Planting Near

  • Celery
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Saving Lettuce Seeds

🌾 Save Your Own Lettuce Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let plants bolt and flower. Harvest seed heads when fluffy.
Storage Store airtight; viable 6 years at 35°F, under 45% humidity.

Very easy to save. Let a few plants bolt each season.

Recommended for Your Garden

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

🪡
Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

Related Plants

Frequently Asked Questions

When should I plant Lettuce in Zone 4a?

In Zone 4a, plan your Lettuce planting around the average last frost date of May 6. Start seeds indoors around March 25. Direct sow outdoors around April 29. Transplant seedlings around May 6.

Can Lettuce grow in Zone 4a?

Yes, Lettuce can grow well in Zone 4a, hardy in USDA zones 2a through 11b. Zone 4a has a growing season of approximately 145 days, which is sufficient for Lettuce (30-60 days to maturity).

When can I harvest Lettuce in Zone 4a?

In Zone 4a, expect to harvest Lettuce from June 10 – August 19. Lettuce takes 30-60 days from planting to harvest.

What is the last frost date for Zone 4a?

The average last spring frost in Zone 4a is around May 6, and the first fall frost is around September 28. This gives a growing season of approximately 145 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Lettuce?

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

🌱

Your Zone 4a Garden Planner — Free

A 22-page printable planner tailored to Zone 4a. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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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: June 2026.

Sources & credits

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