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When to Plant Begonias in Blanco County, TX

Blanco County, Texas Zone 8b June

Your June planting checklist for Blanco County, Texas

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 8
Avg. first frost November 21
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Harvest begonias as they ripen

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

Get ahead of July
  • 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.

Blanco County, Texas is in USDA Zone 8b. The average last spring frost is March 8 and the first fall frost is November 21, giving you a growing season of approximately 258 days.

At an elevation of 4,826 feet, Blanco County receives approximately 61.5 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Begonias during the growing season. Clay soil retains moisture well for Begonias, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Begonias root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Blanco County, TX (Zone 8b) Long season
258 days
Last Spring Frost March 8
258 growing days
First Fall Frost November 21
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Blanco County Soil Profile

Soil Type

Clay

Soil pH

7.1-7.7

Drainage

Well Drained

Begonias Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Dec 21 Transplant: Feb 15 🌸 Bloom: Apr 26 – Sep 27
Recommended (50%) ✓ Fits season (48 days to spare)
Start indoors: Dec 28 Transplant: Feb 22 🌸 Bloom: May 3 – Oct 4
Safe Start (90%) ✓ Fits season (37 days to spare)
Start indoors: Jan 27 Transplant: Mar 24 🌸 Bloom: Jun 2 – Nov 3

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 Blanco County

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

Soil pH

Your soil pH (7.1–7.7) is more alkaline than Begonias prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Blanco County is workable for Begonias. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Begonias.

How to Plant Begonias

8"
Between Plants
10"
Between Rows

Succession Planting Begonias

4
successive plantings in your 258-day season

Sow every 8 weeks. Last sowing by Aug 23 to harvest before frost.

Begonias Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.6" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 5.8" 0" ✅ Rainfall sufficient
May 4.3" 10.3" 0" ✅ Rainfall sufficient
Jun 4.3" 9.9" 0" ✅ Rainfall sufficient
Jul 4.3" 7.7" 0" ✅ Rainfall sufficient
Aug 4.3" 6.7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.4" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Blanco 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 ~1,400 GDD — county provides 4,515 GDD Excellent fit

Begonias Planting Timeline — Blanco County, TX

Begonias Planting Calendar

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors February 22 Feb 22 – Mar 8
Bloom May 3 May 3 – Oct 4

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

258 days in Blanco County

Growing Tips for Begonias in Blanco County

Direct sow Begonias outdoors after March 08 in Blanco County when soil has warmed and frost danger has passed.

With Blanco County's clay soil (36% clay), work in 3-4 inches of compost before planting Begonias. Avoid tilling when soil is wet to prevent compaction.

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 Blanco County, TX?

Blanco County is in Zone 8b with an average last frost of March 8. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.

What planting zone is Blanco County, TX?

Blanco County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 8 and first fall frost is November 21.

🌱

Your Blanco County Garden Planner — Free

A 22-page printable planner built for Blanco County (Zone 8b). 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 Blanco County, TX. 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.