When to Plant Snapdragon in Whitman County, WA
Your June planting checklist for Whitman County, Washington
Each item below is timed to Whitman County, Washington's frost dates and soil temperatures. Skip nothing, stress about nothing.
A few tasks this June that'll pay off in July
- Starting indoors: snapdragon
- 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.
Whitman County, Washington is in USDA Zone 6b. The average last spring frost is May 10 and the first fall frost is September 29, giving you a growing season of approximately 142 days.
At an elevation of 1,541 feet, Whitman County receives approximately 14.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Snapdragon during the growing season. With low rainfall, drip irrigation is essential for growing Snapdragon successfully. Mulch heavily to conserve soil moisture.
Whitman County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
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 Whitman County
How your county's soil matches Snapdragon's growing requirements.
Soil pH
Your soil pH (5.5–6.7) is more acidic than Snapdragon prefers (6.2–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Whitman County is excellent for Snapdragon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Snapdragon will thrive.
How to Plant Snapdragon
Succession Planting Snapdragon
Sow every 8 weeks. Last sowing by Jun 21 to harvest before frost.
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 | — | 2.2" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1.2" | 0" | ❄️ Dormant |
| May | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Jun | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Jul | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Aug | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Sep | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Whitman 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 — Whitman County, WA
Snapdragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | April 19 | Apr 19 – May 10 |
| Bloom | July 19 | Jul 19 – Oct 4 |
· 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6.2–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6b
📆 Growing Season
142 days in Whitman County
Growing Tips for Snapdragon in Whitman County
Direct sow Snapdragon outdoors after May 10 in Whitman County when soil has warmed and frost danger has passed.
Whitman County receives only 14" of rain annually. Snapdragon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Whitman County, WA?
Whitman County is in Zone 6b with an average last frost of May 10. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Whitman County, WA?
Whitman County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 10 and first fall frost is September 29.
Your Whitman County Garden Planner — Free
A 22-page printable planner built for Whitman County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.