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When to Plant Lobelia in Webster County, NE

Webster County, Nebraska Zone 5b August

This month in Webster County, Nebraska

We've pulled the most time-sensitive tasks for Webster County, Nebraska this August and put them front and centre. Tackle them in order.

Avg. last frost April 26
Avg. first frost October 12
Soil temp (4") 79°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs
  1. Harvest lobelia as they ripen

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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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, Nebraska is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 12, giving you a growing season of approximately 169 days.

At an elevation of 925 feet, Webster County receives approximately 23.2 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lobelia during the growing season.

Annual Blooms in Spring Pollinator-friendly
Webster County, NE (Zone 5b) Moderate season
169 days
Last Spring Frost April 26
169 growing days
First Fall Frost October 12

Webster County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Feb 11 Transplant: Apr 15 🌸 Bloom: Jun 10 – Aug 26
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🌸 Bloom: Jun 14 – Aug 30
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Mar 2 Transplant: May 4 🌸 Bloom: Jun 29 – Sep 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 (6.7–7.8) is more alkaline than Lobelia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

2
successive plantings in your 169-day season

Sow every 8 weeks. Last sowing by Jul 24 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 764 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 2.7" 1.6" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.7" 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 ~1,144 GDD — county provides 2,577 GDD Excellent fit

Lobelia Planting Timeline — Webster County, NE

Lobelia Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors April 19 Apr 19 – May 3
Bloom June 14 Jun 14 – Aug 30

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

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_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

169 days in Webster County

Growing Tips for Lobelia in Webster County

Direct sow Lobelia outdoors after April 26 in Webster County when soil has warmed and frost danger has passed.

Webster County receives only 23" of rain annually. Lobelia needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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, NE?

Webster County is in Zone 5b with an average last frost of April 26. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Webster County, NE?

Webster County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 12.

🌱

Your Webster County Garden Planner — Free

A 22-page printable planner built for Webster County (Zone 5b). 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, NE. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.