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When to Plant Snapdragon in USDA Zone 3b

Zone 3b Zone 3b June

This month in Zone 3b

Welcome to June in Zone 3b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 16
Avg. first frost September 22
Looking ahead to July
  • First harvests: snapdragon
Get the full Zone 3b Garden Planner — free →

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.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
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Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Snapdragon Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. Click any state to see the Snapdragon planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Snapdragon Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors May 10 May 10 – May 24
Bloom July 19 Jul 19 – Sep 6

· 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors
June
July Bloom
August Bloom
September Bloom
October
November
December

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

70–100 days

Soil pH

6.2 – 7

Zone Temperature Range

-35°F to -30°F average annual minimum

Growing Season

135 days (Zone 3b average)

Planting Specifications

Plant Spacing9 inches apart
Row Spacing12 inches between rows

Succession Planting Snapdragon in Zone 3b

2
successive plantings in Zone 3b's ~135-day season

Sow every 8 weeks for continuous harvest throughout the season.

Growing Tips for Snapdragon in Zone 3b

Zone 3b has a short growing season (~135 days). Start Snapdragon indoors early and use season-extension techniques like row covers and cold frames.

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

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Saving Snapdragon Seeds

Recommended for Your Garden

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

🪡
Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

Related Plants

Frequently Asked Questions

When should I plant Snapdragon in Zone 3b?

In Zone 3b, plan your Snapdragon planting around the average last frost date of May 10. Start seeds indoors around February 22. Transplant seedlings around May 10.

Can Snapdragon grow in Zone 3b?

Yes, Snapdragon can grow well in Zone 3b, hardy in USDA zones 2a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Snapdragon (70-100 days to maturity).

When can I harvest Snapdragon in Zone 3b?

In Zone 3b, expect to harvest Snapdragon from July 19 – September 6. Snapdragon takes 70-100 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Snapdragon?

Good companion plants for Snapdragon include Lettuce, Carrots, Sweet Alyssum, Lobelia. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Zone 3b Garden Planner — Free

A 22-page printable planner tailored to Zone 3b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — 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.