Blog

When to Plant Borage in USDA Zone 4b

Zone 4b Zone 4b May

Your May game plan for Zone 4b

Your garden in Zone 4b is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 11
Avg. first frost October 2
  1. Get borage in the ground

    Your last frost (May 11) has passed. These warm-season crops can handle outdoor soil now.

  2. Direct-sow borage

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Get ahead of June
  • Starting indoors: borage
  • First harvests: borage
Get your free Zone 4b 2026 Planting Guide →

Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.

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.

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

Borage 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 Borage planting schedule for that location.

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

Borage Planting Calendar — Zone 4b

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 24 Apr 24 – May 15
Harvest June 19 Jun 19 – Aug 7
Fall Sowing July 11 Jul 11 – Jul 25

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors 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.

Share this guide:

Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

Days to Maturity

50–60 days

Soil pH

6 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

155 days (Zone average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing8 inches apart
Row Spacing12 inches between rows

Succession Planting Borage in Zone

3
successive plantings in Zone 's ~155-day season

Sow every 5.7 weeks for continuous harvest throughout the season.

Growing Tips for Borage in Zone

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

Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.

Companion Planting

Good Companions

Best Seller
The Gardener's Encyclopedia to Companion Planting

The Gardener's Encyclopedia to Companion Planting

$27 $293 value

The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.

  • Proven pairings for 200+ vegetables, herbs, flowers, and fruits
  • Full seed-starting + planting schedule with timing and spacing
  • Bonus: square-foot gardening guide + printable seasonal planners
See what's inside →

Saving Borage Seeds

Recommended for Your Garden

🪴
Fabric Grow Bags $10-25

Breathable fabric pots that promote healthy root growth and prevent overwatering.

🏺
Self-Watering Planters $15-40

Built-in reservoir keeps herbs and greens consistently watered with less effort.

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

Related Plants

Frequently Asked Questions

When should I plant Borage in Zone 4b?

In Zone 4b, plan your Borage 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 April 24.

Can Borage grow in Zone 4b?

Yes, Borage 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 Borage (50-60 days to maturity).

When can I harvest Borage in Zone 4b?

In Zone 4b, expect to harvest Borage from June 19 – August 7. Borage takes 50-60 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 Borage?

Good companion plants for Borage include Tomatoes, Squash Summer, Strawberries. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. 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: May 2026.

Sources & credits

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