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When to Plant Ranunculus in Iron County, UT

Iron County, Utah Zone 6b June

This month in Iron County, Utah

Your garden in Iron County, Utah is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 21
Avg. first frost October 1
Soil temp (4") 56°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Pick ranunculus

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before July arrives, get these ready
  • Starting indoors: ranunculus
  • First harvests: ranunculus

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Persian ranunculus (Ranunculus asiaticus) produces multi-petaled blooms that rival roses in intricacy and lushness, in a warm palette of reds, oranges, yellows, pinks, and whites. A cornerstone of the specialty cut flower industry, ranunculus produces long, strong stems ideal for bouquets and arrangements. As a cool-season corm, it performs best in the mild shoulder seasons — planted in fall in warm-winter zones, or in early spring where summers arrive quickly. The 'Elegance', 'Amandine', and 'Tecolote' strains are favorites for both home gardens and commercial growers.

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 86°F, providing good warmth for Ranunculus during the growing season.

Bulb Blooms in Spring Pollinator-friendly Good for cutting
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

Ranunculus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Apr 1 Transplant: May 13 🌸 Bloom: Jun 17 – Jul 15
Recommended (50%) ✓ Fits season (70 days to spare)
Start indoors: Apr 9 Transplant: May 21 🌸 Bloom: Jun 25 – Jul 23
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Apr 28 Transplant: Jun 9 🌸 Bloom: Jul 14 – Aug 11

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 Ranunculus's growing requirements.

Soil pH

Your soil pH (6.4–7.8) is more alkaline than Ranunculus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Iron County is excellent for Ranunculus — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Ranunculus

2"
Planting Depth
6"
Between Plants
8"
Between Rows

Ranunculus Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 523 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Ranunculus

Ranunculus needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Ranunculus Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

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

Ranunculus 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.

Ranunculus needs ~1,522 GDD — county provides 1,928 GDD Good fit

Ranunculus Planting Timeline — Iron County, UT

Ranunculus Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 21 May 21 – Jun 4
Bloom June 25 Jun 25 – Jul 23

Plant 2" deep · 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors
June Transplant Outdoors Bloom
July Bloom
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

133 days in Iron County

Growing Tips for Ranunculus in Iron County

Direct sow Ranunculus outdoors after May 21 in Iron County when soil has warmed and frost danger has passed.

Your 133.0-day growing season in Iron County is tight for Ranunculus (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Iron County receives only 20" of rain annually. Ranunculus needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Pre-soak corms (which look like small octopus tentacles) in cool water for 2–4 hours before planting; do not over-soak. Plant with tentacles pointing downward, 1–2 inches deep and 6 inches apart. Ranunculus demand excellent drainage — they rot in soggy soil. In fall-planting zones (7+), plant October–November and allow to root through mild winter; blooms arrive in March–May. In zones 6, start corms indoors in late winter and transplant out after last frost for a late-spring bloom. Keep soil consistently moist but never waterlogged during growth. After foliage yellows (post-bloom), stop watering, let corms dry, lift them, and store in a cool dry place until replanting. In zones 8b–10b, corms can often be left in ground year-round.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Ranunculus in Iron County, UT?

Iron County is in Zone 6b with an average last frost of May 21. Plan your Ranunculus planting based on this frost date — 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.

🌱

Your Iron County Garden Planner — Free

A 22-page printable planner built for Iron County (Zone 6b). 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 Iron County, UT. Local conditions may vary. Last updated: June 2026.

Sources & credits

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