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When to Plant Begonias in Sevier County, UT

Sevier County, Utah Zone 6a June

Your June game plan for Sevier County, Utah

Your Sevier County, Utah garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost May 19
Avg. first frost September 30
Soil temp (4") 44°F
Watering High
Pest pressure High
Daylight 14.7 hrs
Before July arrives, get these ready
  • Starting indoors: begonias

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Wax begonias (Begonia × semperflorens) are the workhorse shade bedding plant of American horticulture, offering continuous bloom from transplant to hard frost. Bronze or green-leaved varieties perform well from deep shade to full sun (in northern zones) and tolerate summer humidity better than most cool- season flowers. A staple of mass plantings, containers, and window boxes.

Sevier County, Utah is in USDA Zone 6a. The average last spring frost is May 19 and the first fall frost is September 30, giving you a growing season of approximately 134 days.

At an elevation of 8,049 feet, Sevier County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Begonias during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Sevier County, UT (Zone 6a) Short season
134 days
Last Spring Frost May 19
134 growing days
First Fall Frost September 30

Sevier County Soil Profile

Soil Type

Loam

Soil pH

6.4-8

Drainage

Well Drained

Begonias Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 27 Transplant: May 15 🌸 Bloom: Jul 24 – Oct 23
Recommended (50%) ✗ May not fit
Start indoors: Mar 10 Transplant: May 26 🌸 Bloom: Aug 4 – Nov 3
Safe Start (90%) ✗ May not fit
Start indoors: Apr 2 Transplant: Jun 18 🌸 Bloom: Aug 27 – Nov 26

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 Sevier County

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

Soil pH

Your soil pH (6.4–8.0) is more alkaline than Begonias prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Begonias.

How to Plant Begonias

8"
Between Plants
10"
Between Rows

Succession Planting Begonias

2
successive plantings in your 134-day season

Sow every 8 weeks. Last sowing by Jul 02 to harvest before frost.

Begonias Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 507 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Begonias

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

Month Begonias Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 4.3" 2.4" 1.9" 💧 Light watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.6" 2.7" 🚿 Regular watering
Aug 4.3" 2.4" 1.9" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Begonias 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.

Begonias needs ~1,280 GDD — county provides 2,144 GDD Excellent fit

Begonias Planting Timeline — Sevier County, UT

Begonias Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors May 26 May 26 – Jun 9
Bloom August 4 Aug 4 – Nov 3

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

134 days in Sevier County

Growing Tips for Begonias in Sevier County

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

Sevier County receives only 21" of rain annually. Begonias needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 10–12 weeks before last frost — seed is dust-fine; surface-sow on moist mix under lights, do not cover. Bottom heat (70–75°F) speeds germination. Transplant after frost; begonias are not direct-sown in practice. Pinch seedlings once for branching. Keep soil evenly moist; avoid waterlogged conditions. Bronze-leaf types tolerate more sun; green- leaf types prefer shade to part-sun.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Begonias in Sevier County, UT?

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

What planting zone is Sevier County, UT?

Sevier County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 19 and first fall frost is September 30.

🌱

Your Sevier County Garden Planner — Free

A 22-page printable planner built for Sevier County (Zone 6a). 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 Sevier 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.