When to Plant Begonias in Clatsop County, OR
Wax begonias (Begonia × semperflorens) are the workhorse shade bedding plant of American horticulture, offering continuous bloom from transplant to hard frost. Bronze or green-leaved varieties perform well from deep shade to full sun (in northern zones) and tolerate summer humidity better than most cool- season flowers. A staple of mass plantings, containers, and window boxes.
Clatsop County, Oregon is in USDA Zone 9a. The average last spring frost is April 12 and the first fall frost is November 4, giving you a growing season of approximately 206 days.
At an elevation of 412 feet, Clatsop County receives approximately 54.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Begonias during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Begonias root diseases.
Clatsop County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.7
Drainage
Well Drained
Monthly Watering Guide for Begonias
Begonias needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Begonias Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.4" | 0" | ❄️ Dormant |
| Feb | — | 5.2" | 0" | ❄️ Dormant |
| Mar | — | 4.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Jul | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Aug | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Sep | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Oct | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Nov | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 9.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Clatsop County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Begonias Planting Timeline — Clatsop County, OR
Begonias Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 1 | Feb 1 – Feb 15 |
| Transplant Outdoors | March 22 | Mar 22 – Apr 5 |
| Bloom | May 31 | May 31 – Nov 29 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors |
| April | Transplant Outdoors |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: N/A
🗺️ USDA Zone
Zone 9a
📆 Growing Season
206 days in Clatsop County
Growing Tips for Clatsop County
Start seeds indoors 10–12 weeks before last frost — seed is dust-fine; surface-sow on moist mix under lights, do not cover. Bottom heat (70–75°F) speeds germination. Transplant after frost; begonias are not direct-sown in practice. Pinch seedlings once for branching. Keep soil evenly moist; avoid waterlogged conditions. Bronze-leaf types tolerate more sun; green- leaf types prefer shade to part-sun.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Begonias in Other Locations
Frequently Asked Questions
When should I plant Begonias in Clatsop County, OR?
Clatsop County is in Zone 9a with an average last frost of April 12. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clatsop County, OR?
Clatsop County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 12 and first fall frost is November 4.
Your Clatsop County Garden Planner — Free
A 22-page printable planner built for Clatsop 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.