When to Plant Snapdragon in Smith County, TN
Top priorities for Smith County, Tennessee gardeners in June
Welcome to June in Zone 7b. These are the moves that will have the biggest impact on your growing season.
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Sow snapdragon in trays indoors
Your window is short. These crops want several weeks of indoor growth before they go outside.
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Bring in the snapdragon
If you can't use it all right away, check the food-preservation section of your planner.
A few tasks this June that'll pay off in 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.
Smith County, Tennessee is in USDA Zone 7b. The average last spring frost is April 10 and the first fall frost is October 28, giving you a growing season of approximately 201 days.
At an elevation of 3,829 feet, Smith County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Snapdragon during the growing season.
Smith County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-7
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 Smith County
How your county's soil matches Snapdragon's growing requirements.
Soil pH
Your soil pH (5.5–7.0) overlaps with Snapdragon's range (6.2–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Smith County is excellent for Snapdragon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Snapdragon.
How to Plant Snapdragon
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Snapdragon
Sow every 8 weeks. Last sowing by Jul 20 to harvest before frost.
For a dedicated fall crop, sow by Sep 02.
Snapdragon Water Budget
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 | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.1" | 0" | ❄️ Dormant |
| Mar | — | 4.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3" | 1.3" | 💧 Light watering |
| May | 4.3" | 3" | 1.3" | 💧 Light watering |
| Jun | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jul | 4.3" | 4" | 0.3" | 💧 Light watering |
| Aug | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Smith 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 — Smith County, TN
Snapdragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 30 | Jan 30 – Feb 13 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | March 13 | Mar 13 – Apr 3 |
| Bloom | June 12 | Jun 12 – Sep 18 |
| Fall Sowing | September 2 | Sep 2 – Sep 16 |
· 9" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Fall Sowing 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 7b
📆 Growing Season
201 days in Smith County
Growing Tips for Snapdragon in Smith County
Direct sow Snapdragon outdoors after April 10 in Smith 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 →
Snapdragon in Other Locations
Frequently Asked Questions
When should I plant Snapdragon in Smith County, TN?
Smith County is in Zone 7b with an average last frost of April 10. Plan your Snapdragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Smith County, TN?
Smith County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 10 and first fall frost is October 28.
Your Smith County Garden Planner — Free
A 22-page printable planner built for Smith County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.