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When to Plant Snapdragon in Franklin County, WA

Franklin County, Washington Zone 7a June

Your June planting checklist for Franklin County, Washington

Here's what deserves your attention in Franklin County, Washington this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 13
Avg. first frost October 23
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 15.6 hrs
  1. Start snapdragon indoors

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Pick snapdragon

    If you can't use it all right away, check the food-preservation section of your planner.

Before July arrives, get these ready
  • First harvests: snapdragon

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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.

Franklin County, Washington is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 23, giving you a growing season of approximately 193 days.

At an elevation of 1,556 feet, Franklin County receives approximately 15.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°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.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Franklin County, WA (Zone 7a) Moderate season
193 days
Last Spring Frost April 13
193 growing days
First Fall Frost October 23
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Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Snapdragon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Jan 21 Transplant: Apr 1 🌸 Bloom: Jun 10 – Sep 2
Recommended (50%) ✓ Fits season (39 days to spare)
Start indoors: Feb 2 Transplant: Apr 13 🌸 Bloom: Jun 22 – Sep 14
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Mar 1 Transplant: May 10 🌸 Bloom: Jul 19 – Oct 11

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 Franklin County

How your county's soil matches Snapdragon's growing requirements.

Soil pH

Your soil pH (5.6–6.6) is more acidic than Snapdragon prefers (6.2–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Franklin County is excellent for Snapdragon — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.5%) — Snapdragon will thrive.

How to Plant Snapdragon

9"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Snapdragon

3
successive plantings in your 193-day season

Sow every 8 weeks. Last sowing by Jul 15 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

Snapdragon Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,131 gal / 100 sq ft

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 2.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 0.6" 3.7" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.6" 3.7" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Franklin 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 needs ~1,488 GDD — county provides 3,377 GDD Excellent fit

Snapdragon Planting Timeline — Franklin County, WA

Snapdragon Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 16 Mar 16 – Apr 6
Bloom June 22 Jun 22 – Sep 14
Fall Sowing August 28 Aug 28 – Sep 11

· 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Direct Sow
April Transplant Outdoors Direct Sow
May
June Bloom
July Bloom
August Fall Sowing Bloom
September Fall Sowing Bloom
October
November
December
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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 7a

📆 Growing Season

193 days in Franklin County

Growing Tips for Snapdragon in Franklin County

Direct sow Snapdragon outdoors after April 13 in Franklin County when soil has warmed and frost danger has passed.

Franklin County receives only 16" 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 →

Frequently Asked Questions

When should I plant Snapdragon in Franklin County, WA?

Franklin County is in Zone 7a with an average last frost of April 13. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, WA?

Franklin County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 23.

🌱

Your Franklin County Garden Planner — Free

A 22-page printable planner built for Franklin County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Franklin County, WA. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.