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When to plant Lobelia in Webster County, KY

In Webster County, Lobelia is a spring-only crop. Plant March 16–March 30 once soil hits 50°F.

When to Plant Lobelia in Webster County, KY

Webster County, Kentucky Zone 7a June

June in the garden — Webster County, Kentucky

Your Webster County, Kentucky garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 6
Avg. first frost October 31
Soil temp (4") 69°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
  1. Fire up the seed-starting tray: lobelia

    You're about 17 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Harvest lobelia as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Get ahead of July
  • First harvests: lobelia

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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.

Webster County, Kentucky is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 31, giving you a growing season of approximately 208 days.

At an elevation of 2,039 feet, Webster County receives approximately 46.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Lobelia during the growing season.

Annual Blooms in Spring Pollinator-friendly
Webster County, KY (Zone 7a) Long season
208 days
Last Spring Frost April 6
208 growing days
First Fall Frost October 31

Webster County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Jan 25 Transplant: Mar 8 🌸 Bloom: May 3 – Jul 26
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Feb 2 Transplant: Mar 16 🌸 Bloom: May 11 – Aug 3
Safe Start (90%) ✓ Fits season (96 days to spare)
Start indoors: Feb 13 Transplant: Mar 27 🌸 Bloom: May 22 – Aug 14

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 Webster County

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

Soil pH

Your soil pH (5.7–7.0) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Webster 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

3
successive plantings in your 208-day season

Sow every 8 weeks. Last sowing by Aug 12 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 98 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 4.2" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 5.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Webster 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 ~1,312 GDD — county provides 3,640 GDD Excellent fit

Lobelia Planting Timeline — Webster County, KY

Lobelia Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 16 Mar 16 – Mar 30
Bloom May 11 May 11 – Aug 3

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

208 days in Webster County

Growing Tips for Lobelia in Webster County

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

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 Webster County, KY?

Webster County is in Zone 7a with an average last frost of April 6. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Webster County, KY?

Webster County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 31.

When should I plant Lobelia in Webster County, KY?

In Webster County, KY, plant Lobelia after the last frost (around April 6) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is Webster County, KY for Lobelia?

Webster County sits in USDA Zone 7a. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.

Can Lobelia grow in Webster County's climate?

Yes — Lobelia grows well in Webster County's temperate climate. Webster County averages a 208-day frost-free season, with last frost around April 6 and first frost around October 31.

🌱

Your Webster County Garden Planner — Free

A 22-page printable planner built for Webster County (Zone 7a). 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 Webster County, KY. 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.