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When to plant Borage in Greene County, IA

In Greene County, plant Borage in spring between April 13 and May 4, once soil temps hold above 50°F. Greene County's last frost averages April 27, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between July 27 and August 10 — roughly 50–60 days before the first frost on October 5.

When to Plant Borage in Greene County, IA

Greene County, Iowa Zone 5a June

This month in Greene County, Iowa

A quick June briefing for Greene County, Iowa gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 27
Avg. first frost October 5
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Sow borage in trays indoors

    You're about 15 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Collect borage at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Before July arrives, get these ready
  • First harvests: borage
  • Fall sowing: borage

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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.

Greene County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 5, giving you a growing season of approximately 161 days.

At an elevation of 1,292 feet, Greene County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Borage during the growing season.

Greene County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 27
161 growing days
First Fall Frost October 5

Greene County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Borage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: Jun 10 – Jul 29
Recommended (50%) ✓ Fits season (63 days to spare)
Start indoors: Mar 23 Transplant: Apr 20 🍅 Harvest: Jun 15 – Aug 3
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Apr 6 Transplant: May 4 🍅 Harvest: Jun 29 – Aug 17

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Greene County

How your county's soil matches Borage's growing requirements.

Soil pH

Your soil pH (5.8–6.9) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Greene County is excellent for Borage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Borage will thrive.

How to Plant Borage

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Borage

3
successive plantings in your 161-day season

Sow every 5.7 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Jul 27.

Borage Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Borage

Borage needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Borage Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 3.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 2.1" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greene County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Borage Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Borage needs ~798 GDD — county provides 2,334 GDD Excellent fit

Borage Planting Timeline — Greene County, IA

Borage Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Harvest June 15 Jun 15 – Aug 3
Fall Sowing July 27 Jul 27 – Aug 10

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 Fall Sowing Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Greene County

Growing Tips for Borage in Greene County

Direct sow Borage outdoors after April 27 in Greene County when soil has warmed and frost danger has passed.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Borage in Greene County, IA?

Greene County is in Zone 5a with an average last frost of April 27. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greene County, IA?

Greene County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 5.

When should I plant Borage in Greene County, IA?

In Greene County, IA, plant Borage after the last frost (around April 27) and before the first frost (around October 5). Best results when soil holds above 50°F.

What growing zone is Greene County, IA for Borage?

Greene County sits in USDA Zone 5a. Borage grows reliably in zones 3a through 11b, so it's a good fit here.

Can Borage grow in Greene County's climate?

Yes — Borage grows well in Greene County's temperate climate. Greene County averages a 161-day frost-free season, with last frost around April 27 and first frost around October 5.

🌱

Your Greene County Garden Planner — Free

A 22-page printable planner built for Greene County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Greene County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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