When to Plant Petunia in Klickitat County, WA
Petunias (Petunia x hybrida) are warm-season tender annuals prized for their prolific, trumpet-shaped blooms in nearly every color. They perform from hanging baskets to garden borders and bloom continuously from late spring until frost, provided spent flowers are removed regularly.
Klickitat County, Washington is in USDA Zone 7b. The average last spring frost is April 14 and the first fall frost is October 19, giving you a growing season of approximately 188 days.
At an elevation of 466 feet, Klickitat County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 77°F, so choose short-season varieties of Petunia to ensure they mature before fall.
Klickitat County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.8
Drainage
Well Drained
Monthly Watering Guide for Petunia
Petunia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Petunia Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.4" | 0" | ❄️ Dormant |
| Feb | — | 4.3" | 0" | ❄️ Dormant |
| Mar | — | 4.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| May | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Jun | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Jul | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Aug | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | — | 6.7" | 0" | ❄️ Dormant |
| Dec | — | 6.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Klickitat County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Petunia Planting Timeline — Klickitat County, WA
Petunia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 17 | Feb 17 – Mar 3 |
| Transplant Outdoors | April 14 | Apr 14 – Apr 28 |
| Bloom | June 23 | Jun 23 – Oct 20 |
· 12" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 7b
📆 Growing Season
188 days in Klickitat County
Growing Tips for Klickitat County
Start seeds indoors 8–10 weeks before last frost; seeds need light to germinate — press onto moist mix surface, do not cover. Transplant after last frost once nights stay above 50°F. Pinch back leggy plants mid-summer to encourage bushy re-bloom. Wave/spreading types tolerate light shade but bloom less. Feed every 2 weeks with balanced fertilizer once established.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Petunia in Other Locations
Frequently Asked Questions
When should I plant Petunia in Klickitat County, WA?
Klickitat County is in Zone 7b with an average last frost of April 14. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Klickitat County, WA?
Klickitat County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 14 and first fall frost is October 19.
Your Klickitat County Garden Planner — Free
A 22-page printable planner built for Klickitat County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.