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When to Plant Lobelia in Morris County, TX

Morris County, Texas Zone 8b July

July in the garden — Morris County, Texas

Each item below is timed to Morris County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 12
Avg. first frost November 11
Soil temp (4") 89°F
Watering Low
Pest pressure High
Daylight 14 hrs

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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.

Morris County, Texas is in USDA Zone 8b. The average last spring frost is March 12 and the first fall frost is November 11, giving you a growing season of approximately 244 days.

At an elevation of 185 feet, Morris County receives approximately 69.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°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
Morris County, TX (Zone 8b) Long season
244 days
Last Spring Frost March 12
244 growing days
First Fall Frost November 11

Morris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (185 days to spare)
Start indoors: Jan 9 Transplant: Jan 23 🌸 Bloom: Mar 20 – May 1
Recommended (50%) ✓ Fits season (188 days to spare)
Start indoors: Jan 15 Transplant: Jan 29 🌸 Bloom: Mar 26 – May 7
Safe Start (90%) ✓ Fits season (183 days to spare)
Start indoors: Feb 9 Transplant: Feb 23 🌸 Bloom: Apr 20 – Jun 1

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 Morris County

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

Soil pH

Your soil pH (5.5–6.6) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.

Soil Texture

Sandy soil in Morris 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 (1.9%). Add 2-3 inches of compost before planting Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

4
successive plantings in your 244-day season

Sow every 8 weeks. Last sowing by Aug 23 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.7" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 4.3" 4" 0.3" 💧 Light watering
Apr 4.3" 7.4" 0" ✅ Rainfall sufficient
May 4.3" 11.5" 0" ✅ Rainfall sufficient
Jun 4.3" 11.4" 0" ✅ Rainfall sufficient
Jul 4.3" 8.2" 0" ✅ Rainfall sufficient
Aug 4.3" 9.1" 0" ✅ Rainfall sufficient
Sep 4.3" 6.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Morris 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 ~1,650 GDD — county provides 5,368 GDD Excellent fit

Lobelia Planting Timeline — Morris County, TX

Lobelia Planting Calendar

Activity When Date Range
Start Indoors January 15 Jan 15 – Jan 29
Transplant Outdoors January 29 Jan 29 – Feb 12
Bloom March 26 Mar 26 – May 7

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors
February Transplant Outdoors
March Bloom
April Bloom
May Bloom
June
July
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: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

244 days in Morris County

Growing Tips for Lobelia in Morris County

Direct sow Lobelia outdoors after March 12 in Morris County when soil has warmed and frost danger has passed.

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

With summer highs reaching 96°F in Morris County, provide afternoon shade for Lobelia and water deeply in the morning.

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 Morris County, TX?

Morris County is in Zone 8b with an average last frost of March 12. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Morris County, TX?

Morris County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 12 and first fall frost is November 11.

🌱

Your Morris County Garden Planner — Free

A 22-page printable planner built for Morris County (Zone 8b). 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 Morris 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.