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When to plant Lobelia in Clay County County,

Clay County County sits in cold Zone 6b. Plant Lobelia March 31–April 14 for the single annual harvest; the October 23 first frost closes the window.

When to Plant Lobelia in Clay County, KS

Clay County, Kansas Zone 6b June

Your June planting checklist for Clay County, Kansas

Welcome to June in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 14
Avg. first frost October 23
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Start lobelia indoors

    Label every cell. You will absolutely forget which is which otherwise.

  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.

Clay County, Kansas is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 23, giving you a growing season of approximately 192 days.

At an elevation of 519 feet, Clay County receives approximately 28 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Lobelia during the growing season.

Annual Blooms in Spring Pollinator-friendly
Clay County, KS (Zone 6b) Moderate season
192 days
Last Spring Frost April 14
192 growing days
First Fall Frost October 23

Clay County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Feb 7 Transplant: Mar 28 🌸 Bloom: May 23 – Aug 15
Recommended (50%) ✓ Fits season (66 days to spare)
Start indoors: Feb 10 Transplant: Mar 31 🌸 Bloom: May 26 – Aug 18
Safe Start (90%) ✓ Fits season (63 days to spare)
Start indoors: Feb 23 Transplant: Apr 13 🌸 Bloom: Jun 8 – Aug 31

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 Clay County

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

Soil pH

Your soil pH (6.8–7.8) is more alkaline than Lobelia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Lobelia.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

3
successive plantings in your 192-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,410 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 0.8" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 4.3" 2.6" 1.7" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clay 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 ~1,031 GDD — county provides 2,640 GDD Excellent fit

Lobelia Planting Timeline — Clay County, KS

Lobelia Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors March 31 Mar 31 – Apr 14
Bloom May 26 May 26 – Aug 18

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Clay County

Growing Tips for Lobelia in Clay County

Direct sow Lobelia outdoors after April 14 in Clay 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 Clay County, KS?

Clay County is in Zone 6b with an average last frost of April 14. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, KS?

Clay County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 23.

When should I plant Lobelia in Clay County County, ?

In Clay County County, , plant Lobelia after the last frost (around April 14) and before the first frost (around October 23). Best results when soil holds above 50°F.

What growing zone is Clay County County, for Lobelia?

Clay County County sits in USDA Zone 6b. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.

Can Lobelia grow in Clay County County's climate?

Yes — Lobelia grows well in Clay County County's temperate climate. Clay County County averages a 192-day frost-free season, with last frost around April 14 and first frost around October 23.

🌱

Your Clay County Garden Planner — Free

A 22-page printable planner built for Clay County (Zone 6b). 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 Clay County, KS. 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.