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When to plant Begonias in Union County, FL

Union County's 271-day season only supports one Begonias planting per year. Sow between February 8 and February 22 for the best chance at full maturity before November 27.

When to Plant Begonias in Union County, FL

Union County, Florida Zone 9a June

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Avg. last frost March 1
Avg. first frost November 27
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. It's harvest week for begonias

    If you can't use it all right away, check the food-preservation section of your planner.

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.

Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.

At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Begonias may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Begonias will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Begonias root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Union County, FL (Zone 9a) Year-round
271 days
Last Spring Frost March 1
271 growing days
First Fall Frost November 27

Union County Soil Profile

Soil Type

Sand

Soil pH

5.2-6

Drainage

Well Drained

Begonias Planting Risk Windows

Early Start (70% safe) ✓ Fits season (44 days to spare)
Start indoors: Dec 6 Transplant: Jan 24 🌸 Bloom: Apr 4 – Oct 3
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Dec 21 Transplant: Feb 8 🌸 Bloom: Apr 19 – Oct 18
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Jan 15 Transplant: Mar 5 🌸 Bloom: May 14 – Nov 12

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 Union County

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

Soil pH

Your soil pH (5.2–6.0) overlaps with Begonias's range (5.5–6.5), though not a perfect match.

Soil Texture

Sandy soil in Union County warms quickly in spring but drains fast. Begonias will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Begonias.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Begonias.

How to Plant Begonias

8"
Between Plants
10"
Between Rows

Succession Planting Begonias

4
successive plantings in your 271-day season

Sow every 8 weeks. Last sowing by Aug 29 to harvest before frost.

Begonias Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 870 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 3.1" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 8.1" 0" ✅ Rainfall sufficient
Jul 4.3" 10" 0" ✅ Rainfall sufficient
Aug 4.3" 9" 0" ✅ Rainfall sufficient
Sep 4.3" 7.2" 0" ✅ Rainfall sufficient
Oct 4.3" 4.5" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Union 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 ~1,760 GDD — county provides 5,962 GDD Excellent fit

Begonias Planting Timeline — Union County, FL

Begonias Planting Calendar

Activity When Date Range
Start Indoors December 21 Dec 21 – Jan 4
Transplant Outdoors February 8 Feb 8 – Feb 22
Bloom April 19 Apr 19 – Oct 18

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

271 days in Union County

Growing Tips for Begonias in Union County

Direct sow Begonias outdoors after March 01 in Union County when soil has warmed and frost danger has passed.

Sandy soil in Union County dries quickly — mulch Begonias with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Union County, provide afternoon shade for Begonias and water deeply in the morning.

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 Union County, FL?

Union County is in Zone 9a with an average last frost of March 1. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, FL?

Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.

When should I plant Begonias in Union County, FL?

In Union County, FL, plant Begonias after the last frost (around March 1) and before the first frost (around November 27). Best results when soil holds above 50°F.

What growing zone is Union County, FL for Begonias?

Union County sits in USDA Zone 9a. Begonias grows reliably in zones 2a through 11b, so it's a good fit here.

Can Begonias grow in Union County's climate?

Yes — Begonias grows well in Union County's temperate climate. Union County averages a 271-day frost-free season, with last frost around March 1 and first frost around November 27.

🌱

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A 22-page printable planner built for Union County (Zone 9a). 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 Union County, FL. 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.