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When to Plant Dahlias in Juab County, UT

Juab County, Utah Zone 6b June

June in the garden — Juab County, Utah

Each item below is timed to Juab County, Utah's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 19
Avg. first frost October 2
Soil temp (4") 44°F
Watering High
Pest pressure High
Daylight 14.8 hrs
  1. Begin indoor sowing: dahlias

    You're about 13 weeks out from your last frost — the perfect window to get these germinating indoors.

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Dahlias (Dahlia spp.) are the undisputed stars of the late-summer and fall garden, producing an extraordinary range of flower forms — from compact pompons to dinner plate-sized blooms spanning 12 inches — in virtually every color except true blue. Blooming from midsummer until the first hard frost, a single tuber grows into a massive, flower-laden plant that can produce dozens of cut flowers per week. Modern breeding has expanded the palette and forms dramatically; the American Dahlia Society recognizes over 20 flower forms. Extremely rewarding for gardeners willing to invest in the planting, staking, and (in cold zones) annual lifting of tubers.

Juab County, Utah is in USDA Zone 6b. The average last spring frost is May 19 and the first fall frost is October 2, giving you a growing season of approximately 136 days.

At an elevation of 8,143 feet, Juab County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Dahlias to ensure they mature before fall.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Juab County, UT (Zone 6b) Short season
136 days
Last Spring Frost May 19
136 growing days
First Fall Frost October 2

Juab County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Dahlias Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 14 Transplant: May 19 🌸 Bloom: Aug 4 – Nov 24
Recommended (50%) ✗ May not fit
Start indoors: Apr 21 Transplant: May 26 🌸 Bloom: Aug 11 – Dec 1
Safe Start (90%) ✗ May not fit
Start indoors: May 12 Transplant: Jun 16 🌸 Bloom: Sep 1 – Dec 22

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 Juab County

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

Soil pH

Your soil pH (6.5–7.6) overlaps with Dahlias's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Dahlias.

How to Plant Dahlias

5"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Dahlias

2
successive plantings in your 136-day season

Sow every 8 weeks. Last sowing by Jun 04 to harvest before frost.

Dahlias Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 407 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Dahlias

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

Month Dahlias Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Dahlias 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.

Dahlias needs ~1,235 GDD — county provides 1,768 GDD Excellent fit

Dahlias Planting Timeline — Juab County, UT

Dahlias Planting Calendar

Activity When Date Range
Start Indoors April 21 Apr 21 – May 5
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 26 May 26 – Jun 16
Bloom August 11 Aug 11 – Dec 1

Plant 5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

136 days in Juab County

Growing Tips for Dahlias in Juab County

Direct sow Dahlias outdoors after May 19 in Juab County when soil has warmed and frost danger has passed.

Common pests for Dahlias in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Juab County receives only 23" of rain annually. Dahlias needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant tubers after all danger of frost has passed and soil temperature reaches 60°F — typically 1–2 weeks after last frost in most zones. Lay tubers horizontally 4–6 inches deep with the eye (growth point) facing up. Do not water until sprouts emerge; wet soil rots dormant tubers. Stake tall varieties (over 3 feet) at planting time to avoid root disturbance later. Pinch growing tips at 12–16 inches to encourage branching and more blooms. Deadhead regularly to extend the blooming season. In zones 8b and warmer, tubers can overwinter in the ground with a layer of mulch. In zones 3–8a, lift tubers after the first killing frost, cure for a week, and store in slightly damp vermiculite or peat at 40–50°F until spring. Divide tubers every year or two; each division must have an eye (bud) to grow.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Dahlias in Juab County, UT?

Juab County is in Zone 6b with an average last frost of May 19. Plan your Dahlias planting based on this frost date — see the calendar above for exact timing.

What planting zone is Juab County, UT?

Juab County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is May 19 and first fall frost is October 2.

🌱

Your Juab County Garden Planner — Free

A 22-page printable planner built for Juab 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 Juab 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.