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When to Plant Irises in Bountiful, UT

Bountiful, UT Zone 7a June

June in Bountiful, UT — your action list

We've pulled the most time-sensitive tasks for Bountiful, UT this June and put them front and centre. Tackle them in order.

Avg. last frost May 6
Avg. first frost October 10
Soil temp (4") 59°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
Coming up in July — start thinking about
  • First harvests: irises

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Bearded Iris (Iris germanica) are among the most regal flowers of the late-spring garden, producing elegantly ruffled blooms in virtually every color of the rainbow — often in spectacular bicolor combinations. Named for the fuzzy "beard" on the lower falls (petals), bearded irises grow from thick horizontal rhizomes that spread to form dense clumps over time. Individual blooms last only a few days, but a well-established clump produces successive flowers over 3–4 weeks. Many are intensely fragrant. Native iris species including blue flag iris (I. versicolor) and Virginia iris (I. virginica) are excellent choices for wet or native garden settings.

Bountiful, Utah is in USDA Zone 7a. The average last spring frost is May 6 and the first fall frost is October 10, giving you a growing season of approximately 157 days.

At an elevation of 4,567 feet, Davis County receives approximately 16.6 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Irises during the growing season. With low rainfall, drip irrigation is essential for growing Irises successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Bountiful, UT (Zone 7a) Moderate season
157 days
Last Spring Frost May 6
157 growing days
First Fall Frost October 10

Bountiful Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Irises Planting Risk Windows

Early Start (70% safe) ✓ Fits season (65 days to spare)
Transplant: May 3 🌸 Bloom: Jun 21 – Jul 26
Recommended (50%) ✓ Fits season (66 days to spare)
Transplant: May 13 🌸 Bloom: Jul 1 – Aug 5
Safe Start (90%) ✓ Fits season (50 days to spare)
Transplant: Jun 17 🌸 Bloom: Aug 5 – Sep 9

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 Bountiful

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

Soil pH

Your soil pH (6.5–7.6) is more alkaline than Irises prefers (6.8–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Irises.

How to Plant Irises

0.5"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Irises

3
successive plantings in your 157-day season

Sow every 6.9 weeks. Last sowing by Jul 02 to harvest before frost.

Irises Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 94 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Irises

Irises 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 Irises Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.9" 0" ❄️ Dormant
May 2.2" 1.7" 0.5" 💧 Light watering
Jun 2.2" 1" 1.2" 🚿 Regular watering
Jul 2.2" 1.7" 0.5" 💧 Light watering
Aug 2.2" 2" 0.2" 💧 Light watering
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Irises 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.

Irises needs ~1,460 GDD — county provides 2,865 GDD Excellent fit

Irises Planting Timeline — Bountiful, UT

Irises Planting Calendar

Activity When Date Range
Transplant Outdoors May 13 May 13 – May 27
Bloom July 1 Jul 1 – Aug 5

Plant 0.5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6.8–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

157 days in Davis County

Growing Tips for Irises in Bountiful

Direct sow Irises outdoors after May 06 in Davis County when soil has warmed and frost danger has passed.

Davis County receives only 17" of rain annually. Irises needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant rhizomes in late summer to early fall (July–September) after bloom season, setting them horizontally with the top of the rhizome at or just slightly below soil surface — never deeply buried. Full sun is essential for best bloom; at least 6 hours. Well-drained soil is critical; wet rhizomes rot in winter. After bloom, remove flower stalks but leave foliage until it browns in fall. Divide every 3–5 years in late summer when clumps become congested (crowded rhizomes stop blooming). Iris borer is the primary pest — remove and destroy affected fans. Year 2+ after division delivers the most bloom; freshly divided rhizomes may have limited or no bloom in their first season.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

🌱

Your Davis County Garden Planner — Free

A 22-page printable planner built for Davis County (Zone 7a). 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 Davis County, UT. Local conditions may vary. Last updated: June 2026.