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When to plant Dahlias in Dillingham Census Area, AK

Plant Dahlias in Dillingham Census Area, 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 Dahlias in Dillingham Census Area, AK

Dillingham Census Area, Alaska Zone 4b June

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

Your Dillingham Census Area, Alaska garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

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

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Dahlias (Dahlia spp.) are the undisputed stars of the late-summer and fall garden, producing an extraordinary range of flower forms — from compact pompons to dinner plate-sized blooms spanning 12 inches — in virtually every color except true blue. Blooming from midsummer until the first hard frost, a single tuber grows into a massive, flower-laden plant that can produce dozens of cut flowers per week. Modern breeding has expanded the palette and forms dramatically; the American Dahlia Society recognizes over 20 flower forms. Extremely rewarding for gardeners willing to invest in the planting, staking, and (in cold zones) annual lifting of tubers.

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

Bulb Blooms in Summer Pollinator-friendly Good for cutting
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

Dahlias Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jul 29 – Oct 7
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jul 29 – Oct 7
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jul 29 – Oct 7

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 Dahlias's growing requirements.

Soil pH

Your soil pH (5.0–6.2) is more acidic than Dahlias prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Dahlias.

Organic Matter

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

How to Plant Dahlias

5"
Planting Depth
18"
Between Plants
24"
Between Rows

Dahlias 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 Dahlias

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

Month Dahlias 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.

Dahlias 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.

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

Dahlias Planting Timeline — Dillingham Census Area, AK

Dahlias Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 15 May 15 – Jun 5
Bloom August 14 Aug 14 – Oct 23

Plant 5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
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

70–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4b

📆 Growing Season

128 days in Dillingham Census Area

Growing Tips for Dahlias in Dillingham Census Area

Your 128.0-day growing season in Dillingham Census Area is tight for Dahlias (70.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Dahlias in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant tubers after all danger of frost has passed and soil temperature reaches 60°F — typically 1–2 weeks after last frost in most zones. Lay tubers horizontally 4–6 inches deep with the eye (growth point) facing up. Do not water until sprouts emerge; wet soil rots dormant tubers. Stake tall varieties (over 3 feet) at planting time to avoid root disturbance later. Pinch growing tips at 12–16 inches to encourage branching and more blooms. Deadhead regularly to extend the blooming season. In zones 8b and warmer, tubers can overwinter in the ground with a layer of mulch. In zones 3–8a, lift tubers after the first killing frost, cure for a week, and store in slightly damp vermiculite or peat at 40–50°F until spring. Divide tubers every year or two; each division must have an eye (bud) to grow.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

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

In Dillingham Census Area, AK, plant Dahlias 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, AK for Dahlias?

Dillingham Census Area sits in USDA Zone 4b. Dahlias grows reliably in zones 3a through 10b, so it's a good fit here.

Can Dahlias grow in Dillingham Census Area's climate?

Yes — Dahlias grows well in Dillingham Census Area's temperate climate. Dillingham Census Area 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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