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When to Plant Snapdragon in Grimes County, TX

Grimes County, Texas Zone 9a July

This month in Grimes County, Texas

Welcome to July in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 25
Avg. first frost December 1
Soil temp (4") 90°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. It's harvest week for snapdragon

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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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.

Grimes County, Texas is in USDA Zone 9a. The average last spring frost is February 25 and the first fall frost is December 1, giving you a growing season of approximately 279 days.

At an elevation of 33 feet, Grimes County receives approximately 65.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Snapdragon during the growing season. Sandy soil warms quickly in spring — great for early planting — but Snapdragon will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Snapdragon root diseases.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Grimes County, TX (Zone 9a) Year-round
279 days
Last Spring Frost February 25
279 growing days
First Fall Frost December 1

Grimes County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.5

Drainage

Well Drained

Snapdragon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (129 days to spare)
Transplant: Jan 15 🌸 Bloom: Mar 19 – Jul 16
Recommended (50%) ✓ Fits season (125 days to spare)
Transplant: Jan 28 🌸 Bloom: Apr 1 – Jul 29
Safe Start (90%) ✓ Fits season (128 days to spare)
Transplant: Feb 11 🌸 Bloom: Apr 15 – Aug 12

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 Grimes County

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

Soil pH

Your soil pH (5.8–6.5) is more acidic than Snapdragon prefers (6.2–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Grimes County warms quickly in spring but drains fast. Snapdragon will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Snapdragon.

Organic Matter

Organic matter is low (1.7%). Add 2-3 inches of compost before planting Snapdragon.

How to Plant Snapdragon

9"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Snapdragon

4
successive plantings in your 279-day season

Sow every 8 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Sep 08.

Snapdragon Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 963 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 1.9" 0" ❄️ Dormant
Feb 4.3" 2.1" 2.2" 🚿 Regular watering
Mar 4.3" 4.7" 0" ✅ Rainfall sufficient
Apr 4.3" 6" 0" ✅ Rainfall sufficient
May 4.3" 9.9" 0" ✅ Rainfall sufficient
Jun 4.3" 9.9" 0" ✅ Rainfall sufficient
Jul 4.3" 8.3" 0" ✅ Rainfall sufficient
Aug 4.3" 8.3" 0" ✅ Rainfall sufficient
Sep 4.3" 6.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 4.3" 1.7" 2.6" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Grimes 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 ~1,551 GDD — county provides 5,110 GDD Excellent fit

Snapdragon Planting Timeline — Grimes County, TX

Snapdragon Planting Calendar

Activity When Date Range
Transplant Outdoors January 28 Jan 28 – Feb 11
Direct Sow December 31 Dec 31 – Jan 21
Bloom April 1 Apr 1 – Jul 29
Fall Sowing September 8 Sep 8 – Sep 22

· 9" apart · Rows 12" apart

Month-by-Month Timeline

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

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 9a

📆 Growing Season

279 days in Grimes County

Growing Tips for Snapdragon in Grimes County

Direct sow Snapdragon outdoors after February 25 in Grimes County when soil has warmed and frost danger has passed.

Sandy soil in Grimes County dries quickly — mulch Snapdragon with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Grimes County, TX?

Grimes County is in Zone 9a with an average last frost of February 25. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grimes County, TX?

Grimes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 25 and first fall frost is December 1.

🌱

Your Grimes County Garden Planner — Free

A 22-page printable planner built for Grimes County (Zone 9a). 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 Grimes County, TX. 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.