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When to plant Lobelia in Sumter County, FL

Sumter County sits in cold Zone 9b. Plant Lobelia December 5–December 19 for the single annual harvest; the December 6 first frost closes the window.

When to Plant Lobelia in Sumter County, FL

Sumter County, Florida Zone 9b June

June to-do list for Sumter County, Florida

Here's what deserves your attention in Sumter County, Florida this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost February 6
Avg. first frost December 6
Soil temp (4") 85°F
Watering Low
Pest pressure High
Daylight 13.8 hrs

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Lobelia (Lobelia erinus) is a cool-season annual prized for the intense cobalt blue that is rare among bedding flowers. It blooms most prolifically in spring and early summer but stalls or dies back during heat peaks above 90°F. In zones 3–7 it delivers a long display; in zones 8–9 it is best treated as a spring annual that fades by midsummer. Trailing types cascade beautifully from containers and window boxes.

Sumter County, Florida is in USDA Zone 9b. The average last spring frost is February 6 and the first fall frost is December 6, giving you a growing season of approximately 303 days.

At an elevation of 463 feet, Sumter County receives approximately 60.9 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Lobelia may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lobelia will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.

Annual Blooms in Spring Pollinator-friendly
Sumter County, FL (Zone 9b) Year-round
303 days
Last Spring Frost February 6
303 growing days
First Fall Frost December 6

Sumter County Soil Profile

Soil Type

Sand

Soil pH

5-6.1

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (285 days to spare)
Start indoors: Nov 29 Transplant: Nov 22 🌸 Bloom: Jan 17 – Feb 14
Recommended (50%) ✓ Fits season (282 days to spare)
Start indoors: Dec 12 Transplant: Dec 5 🌸 Bloom: Jan 30 – Feb 27
Safe Start (90%) ✓ Fits season (275 days to spare)
Start indoors: Jan 7 Transplant: Dec 31 🌸 Bloom: Feb 25 – Mar 25

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 Sumter County

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

Soil pH

Your soil pH (5.0–6.1) is more acidic than Lobelia prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Lobelia.

Organic Matter

Organic matter is low (1.4%). Add 2-3 inches of compost before planting Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

5
successive plantings in your 303-day season

Sow every 8 weeks. Last sowing by Sep 17 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,489 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lobelia

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

Month Lobelia Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 4.3" 3.3" 1" 💧 Light watering
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 8" 0" ✅ Rainfall sufficient
Jul 4.3" 8.7" 0" ✅ Rainfall sufficient
Aug 4.3" 8.5" 0" ✅ Rainfall sufficient
Sep 4.3" 7.6" 0" ✅ Rainfall sufficient
Oct 4.3" 6.1" 0" ✅ Rainfall sufficient
Nov 4.3" 2.6" 1.7" 💧 Light watering
Dec 4.3" 2.5" 1.8" 💧 Light watering

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

Lobelia 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.

Lobelia needs ~1,650 GDD — county provides 6,688 GDD Excellent fit

Lobelia Planting Timeline — Sumter County, FL

Lobelia Planting Calendar

Activity When Date Range
Start Indoors December 12 Dec 12 – Dec 26
Transplant Outdoors December 5 Dec 5 – Dec 19
Bloom January 30 Jan 30 – Feb 27

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

303 days in Sumter County

Growing Tips for Lobelia in Sumter County

Direct sow Lobelia outdoors after February 06 in Sumter County when soil has warmed and frost danger has passed.

Sandy soil in Sumter County dries quickly — mulch Lobelia 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 Sumter County, provide afternoon shade for Lobelia and water deeply in the morning.

General growing tips

Start seeds indoors 10–12 weeks before last frost — seed is dust-fine and requires light to germinate; surface-sow and press gently. Keep at 65–70°F. Not reliably direct-sown. Transplant in cool weather, 2–4 weeks before last frost date is acceptable in zones 5+. Shear plants by one-third after the first bloom flush to encourage a second flush in fall. Provide afternoon shade in zones 7+ to extend bloom into summer.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lobelia in Sumter County, FL?

Sumter County is in Zone 9b with an average last frost of February 6. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sumter County, FL?

Sumter County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 6 and first fall frost is December 6.

When should I plant Lobelia in Sumter County, FL?

In Sumter County, FL, plant Lobelia after the last frost (around February 6) and before the first frost (around December 6). Best results when soil holds above 50°F.

What growing zone is Sumter County, FL for Lobelia?

Sumter County sits in USDA Zone 9b. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.

Can Lobelia grow in Sumter County's climate?

Yes — Lobelia grows well in Sumter County's temperate climate. Sumter County averages a 304-day frost-free season, with last frost around February 6 and first frost around December 6.

🌱

Your Sumter County Garden Planner — Free

A 22-page printable planner built for Sumter County (Zone 9b). 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 Sumter County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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