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When to Plant Borage in Dubuque, Iowa (52002)

Location

Dubuque, Iowa

ZIP Code

52002

USDA Zone

5a

Last Frost

Sunday, May 10, 2026

📅 Your 2026 Planting Dates

Direct Sow Outdoors

Sunday, May 17, 2026

Based on last frost Sunday, May 10, 2026 · Zone 5a

Pro tip: Sow Borage directly outdoors 1 week after your last frost date — it needs warm soil.

🌿 Plant Details

Scientific Name Borago officinalis
Days to Maturity 60 days
Mature Height 18-36"
Spread 24"
Type Annual

☀️ Growing Requirements

☀️

Sun

Full Sun to Partial Shade

💧

Water

Moderate

↔️

Spacing

18" apart

🌱

Planting Depth

0.5" deep

Seeds typically germinate in 7-14 days

Ready to Plant Borage in Dubuque?

Get your seeds now so they're ready by Sunday, May 17, 2026.

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🤝 Good Companions

TomatoSquashStrawberryPepper

⚠️ Avoid Planting Near

Fennel
🤝

Full Companion Planting Guide for Borage

See which plants help Borage thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

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🌾 Seed Saving Guide

🟢 Easy
✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Seeds ripen quickly and drop — check daily once flowers fade, or collect from the ground below the plant.

Processing

Collect dark nutlets (seeds) directly — they're large and easy to handle. Dry a few days before storing.

Seed Viability

Up to 3 years when stored cool, dark, and dry.

Pro Tip

Borage self-sows prolifically — expect volunteers every year once established in the garden.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 14 plants of Borage. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Borage in Dubuque, Iowa? +

In Dubuque (Zone 5a), direct sow Borage outdoors around Sunday, May 17, 2026.

What is the last frost date for Dubuque, Iowa? +

The average last spring frost date for Dubuque, Iowa (ZIP 52002) is around Sunday, May 10, 2026. This is based on NOAA climate normals for USDA Zone 5a.

How long does Borage take to grow? +

Borage typically matures in about 60 days from direct sowing. In Dubuque, that means you can expect harvest around Sunday, May 17, 2026 plus 60 days.

Should I start Borage indoors or direct sow in Iowa? +

Borage does best when direct sown outdoors. In Dubuque, sow directly around Sunday, May 17, 2026.

Other Plants for Dubuque

Growing Borage in Zone 5a

Borage (Borago officinalis) is a popular garden vegetable. In Dubuque, Iowa, which is in USDA Hardiness Zone 5a, you should direct sow seeds around Sunday, May 17, 2026.

Your average last frost date is Sunday, May 10, 2026. Borage grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.