When to Plant Dahlias in Pacific County, WA
July in the garden — Pacific County, Washington
Here's what deserves your attention in Pacific County, Washington this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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It's harvest week for dahlias
If you can't use it all right away, check the food-preservation section of your planner.
A few tasks this July that'll pay off in August
- First harvests: dahlias
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.
Pacific County, Washington is in USDA Zone 9a. The average last spring frost is April 18 and the first fall frost is October 29, giving you a growing season of approximately 194 days.
At an elevation of 14 feet, Pacific County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Dahlias during the growing season.
Pacific County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.2
Drainage
Well Drained
Dahlias Planting Risk Windows
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 Pacific County
How your county's soil matches Dahlias's growing requirements.
Soil pH
Your soil pH (5.6–6.2) is more acidic than Dahlias prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Pacific County is excellent for Dahlias — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.5%) — Dahlias will thrive.
How to Plant Dahlias
Succession Planting Dahlias
Sow every 8 weeks. Last sowing by Jul 01 to harvest before frost.
Dahlias Water Budget
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 | — | 7.2" | 0" | ❄️ Dormant |
| Feb | — | 5" | 0" | ❄️ Dormant |
| Mar | — | 4.5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Jun | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jul | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Aug | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Oct | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Nov | — | 8" | 0" | ❄️ Dormant |
| Dec | — | 6.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Pacific County). 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 Planting Timeline — Pacific County, WA
Dahlias Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Bloom | June 27 | Jun 27 – Dec 26 |
Plant 5" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | Bloom |
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 9a
📆 Growing Season
194 days in Pacific County
Growing Tips for Dahlias in Pacific County
Direct sow Dahlias outdoors after April 18 in Pacific County when soil has warmed and frost danger has passed.
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 →
Dahlias in Other Locations
Frequently Asked Questions
When should I plant Dahlias in Pacific County, WA?
Pacific County is in Zone 9a with an average last frost of April 18. Plan your Dahlias planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pacific County, WA?
Pacific County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is April 18 and first fall frost is October 29.
Your Pacific County Garden Planner — Free
A 22-page printable planner built for Pacific County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.