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When to Plant Begonias in Pend Oreille County, WA

Pend Oreille County, Washington Zone 6a July

July to-do list for Pend Oreille County, Washington

Welcome to July in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 10
Avg. first frost September 23
Soil temp (4") 67°F
Watering Critical
Pest pressure High
Daylight 15.5 hrs
  1. Start begonias indoors

    You're about 10 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Start harvesting begonias

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

August will be here before you know it — start on
  • First harvests: 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.

Pend Oreille County, Washington is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is September 23, giving you a growing season of approximately 136 days.

At an elevation of 3,807 feet, Pend Oreille County receives approximately 13.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Begonias during the growing season. With low rainfall, drip irrigation is essential for growing Begonias successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Pend Oreille County, WA (Zone 6a) Short season
136 days
Last Spring Frost May 10
136 growing days
First Fall Frost September 23

Pend Oreille County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.6

Drainage

Well Drained

Begonias Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 20 Transplant: May 8 🌸 Bloom: Jul 17 – Oct 16
Recommended (50%) ✗ May not fit
Start indoors: Mar 1 Transplant: May 17 🌸 Bloom: Jul 26 – Oct 25
Safe Start (90%) ✗ May not fit
Start indoors: Mar 22 Transplant: Jun 7 🌸 Bloom: Aug 16 – Nov 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 Pend Oreille County

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

Soil pH

Your soil pH (5.3–6.6) overlaps with Begonias's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Begonias.

Organic Matter

Organic matter is excellent (5.0%) — Begonias will thrive.

How to Plant Begonias

8"
Between Plants
10"
Between Rows

Succession Planting Begonias

2
successive plantings in your 136-day season

Sow every 8 weeks. Last sowing by Jun 25 to harvest before frost.

Begonias Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,080 gal / 100 sq ft

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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 0.9" 0" ❄️ Dormant
May 4.3" 0.8" 3.5" 🚿 Regular watering
Jun 4.3" 0.5" 3.8" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.2" 4.1" 🚿 Regular watering
Sep 4.3" 0.6" 3.7" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Pend Oreille 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 ~1,160 GDD — county provides 1,972 GDD Excellent fit

Begonias Planting Timeline — Pend Oreille County, WA

Begonias Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 17 May 17 – May 31
Bloom July 26 Jul 26 – Oct 25

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

136 days in Pend Oreille County

Growing Tips for Begonias in Pend Oreille County

Direct sow Begonias outdoors after May 10 in Pend Oreille County when soil has warmed and frost danger has passed.

Pend Oreille County receives only 13" 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 Pend Oreille County, WA?

Pend Oreille County is in Zone 6a with an average last frost of May 10. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pend Oreille County, WA?

Pend Oreille County, Washington is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is September 23.

🌱

Your Pend Oreille County Garden Planner — Free

A 22-page printable planner built for Pend Oreille 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 Pend Oreille County, WA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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