When to Plant Snapdragon in Clackamas County, OR
Your June game plan for Clackamas County, Oregon
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
-
Bring in the snapdragon
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
July will be here before you know it — start on
- First harvests: snapdragon
Snapdragons (Antirrhinum majus) are classic cool-season annuals whose upright spikes of dragon-lipped flowers are among spring's most dramatic displays. Tolerating light frosts, they bloom from early spring until summer heat shuts them down — then often revive in fall. In zones 9-11 they are grown as fall-planted winter annuals and may re-seed to naturalize.
Clackamas County, Oregon is in USDA Zone 9a. The average last spring frost is April 14 and the first fall frost is October 28, giving you a growing season of approximately 197 days.
At an elevation of 199 feet, Clackamas County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Snapdragon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Snapdragon root diseases.
Clackamas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.3
Drainage
Well Drained
Snapdragon 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 Clackamas County
How your county's soil matches Snapdragon's growing requirements.
Soil pH
Your soil pH (5.7–6.3) is more acidic than Snapdragon prefers (6.2–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Clackamas County is excellent for Snapdragon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.7%) — Snapdragon will thrive.
How to Plant Snapdragon
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Snapdragon
Sow every 8 weeks. Last sowing by Jul 20 to harvest before frost.
For a dedicated fall crop, sow by Aug 05.
Snapdragon Water Budget
Monthly Watering Guide for Snapdragon
Snapdragon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Snapdragon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.3" | 0" | ❄️ Dormant |
| Feb | — | 5.3" | 0" | ❄️ Dormant |
| Mar | — | 4.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Jul | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Aug | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Sep | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Oct | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Nov | — | 8.2" | 0" | ❄️ Dormant |
| Dec | — | 8.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clackamas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Snapdragon 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.
Snapdragon Planting Timeline — Clackamas County, OR
Snapdragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | March 17 | Mar 17 – Mar 31 |
| Direct Sow | February 17 | Feb 17 – Mar 10 |
| Bloom | May 19 | May 19 – Sep 15 |
| Fall Sowing | August 5 | Aug 5 – Aug 19 |
· 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Fall Sowing Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6.2–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
197 days in Clackamas County
Growing Tips for Snapdragon in Clackamas County
Direct sow Snapdragon outdoors after April 14 in Clackamas County when soil has warmed and frost danger has passed.
General growing tips
Start indoors 10-12 weeks before last frost; seeds need light to germinate — press into moist medium and do not cover. Transplant after hardening off, even if light frosts remain. Pinch seedlings once to encourage branching. Deadhead to prolong blooming. In zones 8-11, sow in fall for a winter-to-spring show. Tall varieties (24-36") make excellent cut flowers.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Snapdragon in Other Locations
Frequently Asked Questions
When should I plant Snapdragon in Clackamas County, OR?
Clackamas County is in Zone 9a with an average last frost of April 14. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clackamas County, OR?
Clackamas County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 14 and first fall frost is October 28.
Your Clackamas County Garden Planner — Free
A 22-page printable planner built for Clackamas 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.