When to Plant Snapdragon in Collin County, TX
This month in Collin County, Texas
Welcome to June in Zone 8b. These are the moves that will have the biggest impact on your growing season.
-
Collect snapdragon at their peak
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Get ahead of July
- First harvests: snapdragon
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.
Collin County, Texas is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.
At an elevation of 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94°F, providing good warmth for Snapdragon during the growing season. Clay soil retains moisture well for Snapdragon, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Snapdragon root diseases.
Collin County Soil Profile
Soil Type
Clay
Soil pH
7.3-7.8
Drainage
Well Drained
Snapdragon Planting Risk Windows
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 Collin County
How your county's soil matches Snapdragon's growing requirements.
Soil pH
Your soil pH (7.3–7.8) is more alkaline than Snapdragon prefers (6.2–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Heavy clay soil (43% clay) in Collin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Snapdragon.
How to Plant Snapdragon
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Snapdragon
Sow every 8 weeks. Last sowing by Aug 12 to harvest before frost.
For a dedicated fall crop, sow by Sep 11.
Snapdragon Water Budget
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 2.2" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 6.9" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 10.2" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 9.9" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Collin 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 Planting Timeline — Collin County, TX
Snapdragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 30 | Dec 30 – Jan 13 |
| Transplant Outdoors | February 17 | Feb 17 – Mar 3 |
| Direct Sow | January 27 | Jan 27 – Feb 17 |
| Bloom | April 28 | Apr 28 – Sep 1 |
| Fall Sowing | September 11 | Sep 11 – Sep 25 |
· 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Fall Sowing Bloom |
| October | — |
| November | — |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6.2–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 8b
📆 Growing Season
255 days in Collin County
Growing Tips for Snapdragon in Collin County
Direct sow Snapdragon outdoors after March 10 in Collin County when soil has warmed and frost danger has passed.
With Collin County's clay soil (43% clay), work in 3-4 inches of compost before planting Snapdragon. Avoid tilling when soil is wet to prevent compaction.
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 →
Snapdragon in Other Locations
Frequently Asked Questions
When should I plant Snapdragon in Collin County, TX?
Collin County is in Zone 8b with an average last frost of March 10. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Collin County, TX?
Collin County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 20.
Your Collin County Garden Planner — Free
A 22-page printable planner built for Collin County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.