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When to plant Lobelia in Dillingham Census Area County,

Plant Lobelia in Dillingham Census Area County, between May 1 and May 15 — the only viable window. Zone 4b's short season (128 frost-free days) rules out a fall crop.

When to Plant Lobelia in Dillingham Census Area, AK

Dillingham Census Area, Alaska Zone 4b June

Dillingham Census Area, Alaska gardeners: here's your June plan

A quick June briefing for Dillingham Census Area, Alaska gardeners — what's urgent, what's next, and what can wait.

Soil temp (4") 58°F
Watering Moderate
Pest pressure Moderate
Daylight 18.4 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.

Dillingham Census Area, Alaska is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is September 6, giving you a growing season of approximately 128 days.

At an elevation of 410 feet, Dillingham Census Area receives approximately 54 inches of rainfall annually with predominantly silt loam soil. Summer highs average 60°F, so choose short-season varieties of Lobelia to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.

Annual Blooms in Spring Pollinator-friendly
Dillingham Census Area, AK (Zone 4b) Short season
128 days
Last Spring Frost May 1
128 growing days
First Fall Frost September 6
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Dillingham Census Area Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.2

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jun 10 – Aug 12
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jun 10 – Aug 12
Safe Start (90%) ✓ Fits season (64 days to spare)
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jun 10 – Aug 12

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 Dillingham Census Area

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Lobelia prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Lobelia.

Organic Matter

Organic matter is excellent (6.6%) — Lobelia will thrive.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.8″/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 2.6" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 7.3" 0" ✅ Rainfall sufficient
Aug 4.3" 8.4" 0" ✅ Rainfall sufficient
Sep 4.3" 9.5" 0" ✅ Rainfall sufficient
Oct 6.5" 0" ❄️ Dormant
Nov 4.2" 0" ❄️ Dormant
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Dillingham Census Area). 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 ~0 GDD — county provides 0 GDD May not mature

Lobelia Planting Timeline — Dillingham Census Area, AK

Lobelia Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors May 1 May 1 – May 15
Bloom June 26 Jun 26 – Aug 28

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 4b

📆 Growing Season

128 days in Dillingham Census Area

Growing Tips for Dillingham Census Area

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 Dillingham Census Area, AK?

Dillingham Census Area is in Zone 4b with an average last frost of May 1. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dillingham Census Area, AK?

Dillingham Census Area, Alaska is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is September 6.

When should I plant Lobelia in Dillingham Census Area County, ?

In Dillingham Census Area County, , plant Lobelia after the last frost (around May 1) and before the first frost (around September 6). Best results when soil holds above 50°F.

What growing zone is Dillingham Census Area County, for Lobelia?

Dillingham Census Area County sits in USDA Zone 4b. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.

Can Lobelia grow in Dillingham Census Area County's climate?

Yes — Lobelia grows well in Dillingham Census Area County's temperate climate. Dillingham Census Area County averages a 128-day frost-free season, with last frost around May 1 and first frost around September 6.

🌱

Your Dillingham Census Area Garden Planner — Free

A 22-page printable planner built for Dillingham Census Area (Zone 4b). 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 Dillingham Census Area, AK. Local conditions may vary. Last updated: June 2026.

Sources & credits

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