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When to Plant Lobelia in Hall County, TX

Hall County, Texas Zone 7b July

July in Hall County, Texas — your action list

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Hall County, Texas.

Avg. last frost March 31
Avg. first frost November 6
Soil temp (4") 85°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Start harvesting lobelia

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

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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.

Hall County, Texas is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 6, giving you a growing season of approximately 220 days.

At an elevation of 1,213 feet, Hall County receives approximately 52.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Lobelia during the growing season. 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
Hall County, TX (Zone 7b) Long season
220 days
Last Spring Frost March 31
220 growing days
First Fall Frost November 6

Hall County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.4-8.8

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Jan 19 Transplant: Feb 23 🌸 Bloom: Apr 20 – Jun 29
Recommended (50%) ✓ Fits season (122 days to spare)
Start indoors: Jan 27 Transplant: Mar 3 🌸 Bloom: Apr 28 – Jul 7
Safe Start (90%) ✓ Fits season (122 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 Hall County

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

Soil pH

Your soil pH (7.4–8.8) is more alkaline than Lobelia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Hall County warms quickly in spring but drains fast. Lobelia will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

3
successive plantings in your 220-day season

Sow every 8 weeks. Last sowing by Aug 18 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 3.5" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.3" 3.1" 1.2" 💧 Light watering
Apr 4.3" 1.8" 2.5" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 2" 2.3" 🚿 Regular watering
Jul 4.3" 8.9" 0" ✅ Rainfall sufficient
Aug 4.3" 10" 0" ✅ Rainfall sufficient
Sep 4.3" 7.1" 0" ✅ Rainfall sufficient
Oct 4.3" 5.4" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Hall 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 ~1,538 GDD — county provides 4,510 GDD Excellent fit

Lobelia Planting Timeline — Hall County, TX

Lobelia Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors March 3 Mar 3 – Mar 17
Bloom April 28 Apr 28 – Jul 7

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
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 · Natural rainfall sufficient

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

220 days in Hall County

Growing Tips for Lobelia in Hall County

Direct sow Lobelia outdoors after March 31 in Hall County when soil has warmed and frost danger has passed.

Sandy soil in Hall County dries quickly — mulch Lobelia with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Hall County, TX?

Hall County is in Zone 7b with an average last frost of March 31. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hall County, TX?

Hall County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 6.

🌱

Your Hall County Garden Planner — Free

A 22-page printable planner built for Hall 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.

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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 Hall County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

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