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When to Plant Borage in Iron County, UT

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.

Iron County, Utah is in USDA Zone 6b. The average last spring frost is May 21 and the first fall frost is October 1, giving you a growing season of approximately 133 days.

At an elevation of 6,296 feet, Iron County receives approximately 20 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Borage during the growing season.

Iron County, UT (Zone 6b) Short season
133 days
Last Spring Frost May 21
133 growing days
First Fall Frost October 1

Iron County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Apr 8 Transplant: May 6 🍅 Harvest: Jul 1 – Aug 19
Recommended (50%) ✓ Fits season (35 days to spare)
Start indoors: Apr 16 Transplant: May 14 🍅 Harvest: Jul 9 – Aug 27
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: May 5 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 15

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 Iron County

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

Soil pH

Your soil pH (6.4โ€“7.8) is more alkaline than Borage prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Iron County is excellent for Borage โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Borage.

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 133-day season

Sow every 5.7 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Jul 23.

Plant Water Budget

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

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 2" 0" โ„๏ธ Dormant
May 2.2" 2.6" 0" โœ… Rainfall sufficient
Jun 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Jul 2.2" 1.9" 0.3" ๐Ÿ’ง Light watering
Aug 2.2" 2.2" 0" โœ… Rainfall sufficient
Sep 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Oct 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Iron County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 1,928 GDD Excellent fit

Borage Planting Timeline โ€” Iron County, UT

Borage Planting Calendar

Activity When Date Range
Start Indoors April 16 Apr 16 โ€“ Apr 30
Transplant Outdoors May 14 May 14 โ€“ May 28
Direct Sow May 7 May 7 โ€“ May 28
Harvest July 9 Jul 9 โ€“ Aug 27
Fall Sowing July 23 Jul 23 โ€“ Aug 6

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

133 days in Iron County

Growing Tips for Borage in Iron County

Direct sow Borage outdoors after May 21 in Iron 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 Iron County, UT?

Iron County is in Zone 6b with an average last frost of May 21. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Iron County, UT?

Iron County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is May 21 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Iron County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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