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When to plant Snapdragon in Benton County, MN

Benton County sits in cold Zone 4a. Plant Snapdragon May 2–May 16 for the single annual harvest; the October 6 first frost closes the window.

When to Plant Snapdragon in Benton County, MN

Benton County, Minnesota Zone 4a July

What to do in July

Each item below is timed to Benton County, Minnesota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 2
Avg. first frost October 6
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Get snapdragon seeds going inside

    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

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to August
  • 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.

Benton County, Minnesota is in USDA Zone 4a. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.

At an elevation of 1,178 feet, Benton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Snapdragon to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Benton County, MN (Zone 4a) Moderate season
157 days
Last Spring Frost May 2
157 growing days
First Fall Frost October 6

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Snapdragon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Feb 8 Transplant: Apr 26 🌸 Bloom: Jul 5 – Aug 30
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Feb 14 Transplant: May 2 🌸 Bloom: Jul 11 – Sep 5
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Mar 3 Transplant: May 19 🌸 Bloom: Jul 28 – Sep 22

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 Benton County

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

Soil pH

Your soil pH (6.0–7.0) overlaps with Snapdragon's range (6.2–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Snapdragon.

Organic Matter

Organic matter is excellent (4.9%) — Snapdragon will thrive.

How to Plant Snapdragon

9"
Between Plants
12"
Between Rows

Succession Planting Snapdragon

2
successive plantings in your 157-day season

Sow every 8 weeks. Last sowing by Jun 28 to harvest before frost.

Snapdragon Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 359 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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Benton 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 ~1,105 GDD — county provides 2,041 GDD Excellent fit

Snapdragon Planting Timeline — Benton County, MN

Snapdragon Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 – Feb 28
Transplant Outdoors May 2 May 2 – May 16
Bloom July 11 Jul 11 – Sep 5

· 9" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6.2–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

157 days in Benton County

Growing Tips for Snapdragon in Benton County

Direct sow Snapdragon outdoors after May 02 in Benton 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 →

Frequently Asked Questions

When should I plant Snapdragon in Benton County, MN?

Benton County is in Zone 4a with an average last frost of May 2. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benton County, MN?

Benton County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 2 and first fall frost is October 6.

When should I plant Snapdragon in Benton County, MN?

In Benton County, MN, plant Snapdragon after the last frost (around May 2) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Benton County, MN for Snapdragon?

Benton County sits in USDA Zone 4a. Snapdragon grows reliably in zones 2a through 11b, so it's a good fit here.

Can Snapdragon grow in Benton County's climate?

Yes — Snapdragon grows well in Benton County's temperate climate. Benton County averages a 157-day frost-free season, with last frost around May 2 and first frost around October 6.

🌱

Your Benton County Garden Planner — Free

A 22-page printable planner built for Benton County (Zone 4a). 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 Benton County, MN. Local conditions may vary. Last updated: July 2026.

Sources & credits

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