Blog

When to plant Lobelia in Sharp County County,

In Sharp County County, Lobelia is a single-season spring crop — there's no second fall window. Plant February 26–March 12 for an 80-day harvest, finishing well before the November 2 first frost.

When to Plant Lobelia in Sharp County, AR

Sharp County, Arkansas Zone 7b June

Sharp County, Arkansas gardeners: here's your June plan

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

Avg. last frost March 26
Avg. first frost November 2
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.4 hrs
  1. Collect lobelia at their peak

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

Coming up in July — start thinking about
  • First harvests: lobelia

Instant PDF download. No spam, unsubscribe any time.

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.

Sharp County, Arkansas is in USDA Zone 7b. The average last spring frost is March 26 and the first fall frost is November 2, giving you a growing season of approximately 221 days.

At an elevation of 674 feet, Sharp County receives approximately 50.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Lobelia during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.

Annual Blooms in Spring Pollinator-friendly
Sharp County, AR (Zone 7b) Long season
221 days
Last Spring Frost March 26
221 growing days
First Fall Frost November 2

Sharp County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (130 days to spare)
Start indoors: Jan 10 Transplant: Feb 14 🌸 Bloom: Apr 11 – Jun 20
Recommended (50%) ✓ Fits season (123 days to spare)
Start indoors: Jan 22 Transplant: Feb 26 🌸 Bloom: Apr 23 – Jul 2
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Feb 11 Transplant: Mar 18 🌸 Bloom: May 13 – Jul 22

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 Sharp County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

3
successive plantings in your 221-day season

Sow every 8 weeks. Last sowing by Aug 14 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 94 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 3.8" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 4.5" 0" ✅ Rainfall sufficient
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 5.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Sharp 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 ~1,200 GDD — county provides 3,536 GDD Excellent fit

Lobelia Planting Timeline — Sharp County, AR

Lobelia Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors February 26 Feb 26 – Mar 12
Bloom April 23 Apr 23 – Jul 2

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors Transplant Outdoors
March Transplant Outdoors
April Bloom
May Bloom
June Bloom
July Bloom
August
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 7b

📆 Growing Season

221 days in Sharp County

Growing Tips for Lobelia in Sharp County

Direct sow Lobelia outdoors after March 26 in Sharp 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 Sharp County, AR?

Sharp County is in Zone 7b with an average last frost of March 26. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sharp County, AR?

Sharp County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 26 and first fall frost is November 2.

When should I plant Lobelia in Sharp County County, ?

In Sharp County County, , plant Lobelia after the last frost (around March 26) and before the first frost (around November 2). Best results when soil holds above 50°F.

What growing zone is Sharp County County, for Lobelia?

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

Can Lobelia grow in Sharp County County's climate?

Yes — Lobelia grows well in Sharp County County's temperate climate. Sharp County County averages a 221-day frost-free season, with last frost around March 26 and first frost around November 2.

🌱

Your Sharp County Garden Planner — Free

A 22-page printable planner built for Sharp County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sharp County, AR. 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.