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When to plant Snapdragon in Scott County, IA

Scott County sits in USDA Zone 5b. Plant Snapdragon between April 1 (after last frost on April 15) and April 22.

When to Plant Snapdragon in Scott County, IA

Scott County, Iowa Zone 5b July

Top priorities for Scott County, Iowa gardeners in July

Welcome to July in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 15
Avg. first frost October 17
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Start harvesting snapdragon

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

August prep starts now
  • 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.

Scott County, Iowa is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.

At an elevation of 678 feet, Scott County receives approximately 37.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°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
Scott County, IA (Zone 5b) Moderate season
185 days
Last Spring Frost April 15
185 growing days
First Fall Frost October 17

Scott County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Snapdragon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (44 days to spare)
Start indoors: Jan 30 Transplant: Apr 10 🌸 Bloom: Jun 19 – Aug 28
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jun 24 – Sep 2
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Feb 22 Transplant: May 3 🌸 Bloom: Jul 12 – Sep 20

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 Scott County

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

Soil pH

Your soil pH (5.8–6.7) overlaps with Snapdragon's range (6.2–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Snapdragon will thrive.

How to Plant Snapdragon

9"
Between Plants
12"
Between Rows

Succession Planting Snapdragon

3
successive plantings in your 185-day season

Sow every 8 weeks. Last sowing by Jul 09 to harvest before frost.

Snapdragon Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 276 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Scott 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 ~1,041 GDD — county provides 2,266 GDD Excellent fit

Snapdragon Planting Timeline — Scott County, IA

Snapdragon Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 1 Apr 1 – Apr 22
Bloom June 24 Jun 24 – Sep 2

· 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May
June Bloom
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 5b

📆 Growing Season

185 days in Scott County

Growing Tips for Snapdragon in Scott County

Direct sow Snapdragon outdoors after April 15 in Scott 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 Scott County, IA?

Scott County is in Zone 5b with an average last frost of April 15. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Scott County, IA?

Scott County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 17.

When should I plant Snapdragon in Scott County, IA?

In Scott County, IA, plant Snapdragon after the last frost (around April 15) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Scott County, IA for Snapdragon?

Scott County sits in USDA Zone 5b. Snapdragon grows reliably in zones 2a through 11b, so it's a good fit here.

Can Snapdragon grow in Scott County's climate?

Yes — Snapdragon grows well in Scott County's temperate climate. Scott County averages a 185-day frost-free season, with last frost around April 15 and first frost around October 17.

🌱

Your Scott County Garden Planner — Free

A 22-page printable planner built for Scott County (Zone 5b). 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 Scott County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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