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When to Plant Arugula in USDA Zone 4b

Zone 4b Zone 4b July

Your July game plan for Zone 4b

We've pulled the most time-sensitive tasks for Zone 4b this July and put them front and centre. Tackle them in order.

Avg. last frost May 11
Avg. first frost October 2
  1. Harvest arugula as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

  2. Get arugula in for a late-season harvest

    Your first frost is about 12 weeks away — plenty of time for these to mature.

A few tasks this July that'll pay off in August
  • First harvests: arugula
Get the full Zone 4b Garden Planner — free →

Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.

In Zone 4b, the average last spring frost is around May 1 and the first fall frost is around October 3, giving you a growing season of approximately 155 days.

Zone 4b Moderate season
155 days
Last Spring Frost May 1
155 growing days
First Fall Frost October 3

Arugula Planting Timeline — Zone 4b

Where Is USDA Zone 4b?

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

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

Arugula Planting Calendar — Zone 4b

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest June 5 Jun 5 – Aug 7
Fall Sowing July 11 Jul 11 – Jul 25

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 4b Planting Calendar PDF

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

Instant PDF download. No spam, unsubscribe any time.

Growing Conditions

Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

Days to Maturity

30–50 days

Soil pH

6 – 7

Zone Temperature Range

-25°F to -20°F average annual minimum

Growing Season

155 days (Zone 4b average)

Planting Specifications

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

Succession Planting Arugula in Zone 4b

6
successive plantings in Zone 4b's ~155-day season

Sow every 3.4 weeks for continuous harvest throughout the season.

Growing Tips for Arugula in Zone 4b

Zone 4b has a short growing season (~155 days). Start Arugula indoors early and use season-extension techniques like row covers and cold frames.

Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
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Saving Arugula Seeds

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 Arugula in Zone 4b?

In Zone 4b, plan your Arugula planting around the average last frost date of May 1. Start seeds indoors around March 20. Direct sow outdoors around April 24. Transplant seedlings around May 1.

Can Arugula grow in Zone 4b?

Yes, Arugula can grow well in Zone 4b, hardy in USDA zones 3a through 11b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Arugula (30-50 days to maturity).

When can I harvest Arugula in Zone 4b?

In Zone 4b, expect to harvest Arugula from June 5 – August 7. Arugula takes 30-50 days from planting to harvest.

What is the last frost date for Zone 4b?

The average last spring frost in Zone 4b is around May 1, and the first fall frost is around October 3. This gives a growing season of approximately 155 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Arugula?

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

🌱

Your Zone 4b Garden Planner — Free

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

Instant PDF download. No spam, unsubscribe any time.

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: July 2026.

Sources & credits

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