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When to Plant Lobelia in Hemphill County, TX

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.

Hemphill County, Texas is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 23, giving you a growing season of approximately 191 days.

At an elevation of 3,231 feet, Hemphill County receives approximately 53.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Lobelia may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lobelia will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.

Annual Blooms in Spring Pollinator-friendly
Hemphill County, TX (Zone 7a) Moderate season
191 days
Last Spring Frost April 15
191 growing days
First Fall Frost October 23

Hemphill County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Lobelia Planting Timeline — Hemphill County, TX

Lobelia Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors March 25 Mar 25 – Apr 8
Bloom May 20 May 20 – Aug 12

· 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

Moderate — regular watering

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

191 days in Hemphill County

Growing Tips for Hemphill County

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 Hemphill County, TX?

Hemphill County is in Zone 7a with an average last frost of April 15. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hemphill County, TX?

Hemphill County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 23.

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A 22-page printable planner built for Hemphill 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 Hemphill County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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