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When to Plant Lobelia in Middlesex County, VA

Middlesex County, Virginia Zone 8a June

Your June gardening checklist

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

Avg. last frost April 1
Avg. first frost November 4
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
  1. Harvest lobelia as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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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.

Middlesex County, Virginia is in USDA Zone 8a. The average last spring frost is April 1 and the first fall frost is November 4, giving you a growing season of approximately 217 days.

At an elevation of 812 feet, Middlesex County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Lobelia during the growing season.

Annual Blooms in Spring Pollinator-friendly
Middlesex County, VA (Zone 8a) Long season
217 days
Last Spring Frost April 1
217 growing days
First Fall Frost November 4
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Middlesex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (145 days to spare)
Start indoors: Jan 27 Transplant: Feb 17 🌸 Bloom: Apr 14 – Jun 9
Recommended (50%) ✓ Fits season (140 days to spare)
Start indoors: Feb 4 Transplant: Feb 25 🌸 Bloom: Apr 22 – Jun 17
Safe Start (90%) ✓ Fits season (138 days to spare)
Start indoors: Feb 21 Transplant: Mar 14 🌸 Bloom: May 9 – Jul 4

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 Middlesex County

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

Soil pH

Your soil pH (5.7–7.1) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Middlesex 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 (2.7%). Annual compost additions will help Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

3
successive plantings in your 217-day season

Sow every 8 weeks. Last sowing by Aug 16 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 3.8" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 3.3" 1" 💧 Light watering
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 4.3" 2.9" 1.4" 💧 Light watering
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Middlesex 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 ~1,256 GDD — county provides 3,634 GDD Excellent fit

Lobelia Planting Timeline — Middlesex County, VA

Lobelia Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors February 25 Feb 25 – Mar 11
Bloom April 22 Apr 22 – Jun 17

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors
March Transplant Outdoors
April Bloom
May Bloom
June Bloom
July
August
September
October
November
December
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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 8a

📆 Growing Season

217 days in Middlesex County

Growing Tips for Lobelia in Middlesex County

Direct sow Lobelia outdoors after April 01 in Middlesex 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 Middlesex County, VA?

Middlesex County is in Zone 8a with an average last frost of April 1. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Middlesex County, VA?

Middlesex County, Virginia is in USDA Hardiness Zone 8a. The average last spring frost is April 1 and first fall frost is November 4.

🌱

Your Middlesex County Garden Planner — Free

A 22-page printable planner built for Middlesex County (Zone 8a). 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 Middlesex County, VA. 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.