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When to plant Phlox in Dillingham Census Area County,

Plant Phlox in Dillingham Census Area County, between May 15 and June 5 — the only viable window. Zone 4b's short season (128 frost-free days) rules out a fall crop.

When to Plant Phlox in Dillingham Census Area, AK

Dillingham Census Area, Alaska Zone 4b June

Your June game plan for Dillingham Census Area, Alaska

Welcome to June in Zone 4b. These are the moves that will have the biggest impact on your growing season.

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

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Garden Phlox (Phlox paniculata) is a beloved native perennial of eastern North America, producing large, domed clusters of fragrant flowers atop upright stems from mid-summer into fall. Its sweet honey-like fragrance carries on summer evenings and draws hummingbirds, butterflies, and sphinx moths. Modern cultivars offer colors spanning white, pink, salmon, red, purple, and bicolors. A classic cottage garden stalwart, phlox combines well with black-eyed Susans, echinacea, and ornamental grasses in naturalistic plantings. Select mildew-resistant cultivars for best long-term performance.

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 Phlox to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Phlox root diseases.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Dillingham Census Area, AK (Zone 4b) Short season
128 days
Last Spring Frost May 1
128 growing days
First Fall Frost September 6

Dillingham Census Area Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.2

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Feb 4 Transplant: Apr 29 🌸 Bloom: Jul 22 – Sep 30
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Feb 4 Transplant: Apr 29 🌸 Bloom: Jul 22 – Sep 30
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Feb 4 Transplant: Apr 29 🌸 Bloom: Jul 22 – Sep 30

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 Phlox's growing requirements.

Soil pH

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

Soil Texture

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

Drainage

Drainage is adequate for Phlox.

Organic Matter

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

How to Plant Phlox

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Phlox 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 Phlox

Phlox needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Phlox 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.

Phlox 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.

Phlox needs ~0 GDD — county provides 0 GDD May not mature

Phlox Planting Timeline — Dillingham Census Area, AK

Phlox Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 15 May 15 – Jun 5
Bloom August 7 Aug 7 – Oct 16

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–110 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 8–10 weeks before last frost, or transplant container divisions in spring. Named cultivar seeds may not come true; divisions from named plants are the preferred propagation method. Space generously (18–24 inches) and avoid overhead watering to reduce powdery mildew risk. Good air circulation is critical — thin clumps to the strongest 5–7 stems per plant in spring. Deadhead after the primary bloom flush to encourage secondary flowering. Division every 2–3 years in spring keeps plants vigorous. Fall planting of divisions (Zones 5+) is equally effective. Year 2+ plants develop into full clumps with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Phlox in Dillingham Census Area, AK?

Dillingham Census Area is in Zone 4b with an average last frost of May 1. Plan your Phlox 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 Phlox in Dillingham Census Area County, ?

In Dillingham Census Area County, , plant Phlox 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 Phlox?

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

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

Yes — Phlox 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

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