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When to plant Lobelia in Montgomery County County,

Plant Lobelia in Montgomery County County, between January 27 and February 10 — the only viable window. Zone 8b's short season (250 frost-free days) rules out a fall crop.

When to Plant Lobelia in Montgomery County, AL

Montgomery County, Alabama Zone 8b June

Your June game plan for Montgomery County, Alabama

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Montgomery County, Alabama.

Avg. last frost March 10
Avg. first frost November 15
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14.1 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.

Montgomery County, Alabama is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 15, giving you a growing season of approximately 250 days.

At an elevation of 468 feet, Montgomery County receives approximately 62 inches of rainfall annually with predominantly clay loam soil. Summer highs average 92°F, providing good warmth for Lobelia during the growing season. Clay soil retains moisture well for Lobelia, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.

Annual Blooms in Spring Pollinator-friendly
Montgomery County, AL (Zone 8b) Long season
250 days
Last Spring Frost March 10
250 growing days
First Fall Frost November 15

Montgomery County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.3

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (194 days to spare)
Start indoors: Jan 8 Transplant: Jan 22 🌸 Bloom: Mar 19 – Apr 30
Recommended (50%) ✓ Fits season (194 days to spare)
Start indoors: Jan 13 Transplant: Jan 27 🌸 Bloom: Mar 24 – May 5
Safe Start (90%) ✓ Fits season (189 days to spare)
Start indoors: Feb 3 Transplant: Feb 17 🌸 Bloom: Apr 14 – May 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 Montgomery County

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

Soil pH

Your soil pH (5.6–6.3) is more acidic than Lobelia prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Montgomery County is excellent for Lobelia — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

4
successive plantings in your 250-day season

Sow every 8 weeks. Last sowing by Aug 27 to harvest before frost.

Lobelia 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 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 5.7" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4.3" 7.1" 0" ✅ Rainfall sufficient
Apr 4.3" 5.2" 0" ✅ Rainfall sufficient
May 4.3" 4.9" 0" ✅ Rainfall sufficient
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 6.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 5.1" 0" ✅ Rainfall sufficient
Dec 4.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Montgomery 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 ~1,425 GDD — county provides 4,750 GDD Excellent fit

Lobelia Planting Timeline — Montgomery County, AL

Lobelia Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors January 27 Jan 27 – Feb 10
Bloom March 24 Mar 24 – May 5

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

250 days in Montgomery County

Growing Tips for Lobelia in Montgomery County

Direct sow Lobelia outdoors after March 10 in Montgomery County when soil has warmed and frost danger has passed.

With Montgomery County's clay soil (27% clay), work in 3-4 inches of compost before planting Lobelia. 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 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 Montgomery County, AL?

Montgomery County is in Zone 8b with an average last frost of March 10. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Montgomery County, AL?

Montgomery County, Alabama is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 15.

When should I plant Lobelia in Montgomery County County, ?

In Montgomery County County, , plant Lobelia after the last frost (around March 10) and before the first frost (around November 15). Best results when soil holds above 50°F.

What growing zone is Montgomery County County, for Lobelia?

Montgomery County County sits in USDA Zone 8b. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.

Can Lobelia grow in Montgomery County County's climate?

Yes — Lobelia grows well in Montgomery County County's temperate climate. Montgomery County County averages a 250-day frost-free season, with last frost around March 10 and first frost around November 15.

🌱

Your Montgomery County Garden Planner — Free

A 22-page printable planner built for Montgomery 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 Montgomery County, AL. 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.