When to Plant Sunflower in San Augustine County, TX
Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.
San Augustine County, Texas is in USDA Zone 8b. The average last spring frost is March 5 and the first fall frost is November 16, giving you a growing season of approximately 256 days.
At an elevation of 146 feet, San Augustine County receives approximately 62.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
San Augustine County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.4-6.6
Drainage
Well Drained
Plant 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 San Augustine County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (5.4–6.6) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
Sandy soil in San Augustine County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (1.8%). Add 2-3 inches of compost before planting Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Aug 08 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sunflower
Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 8.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 10.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 8.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in San Augustine County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower 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.
Sunflower Planting Timeline — San Augustine County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 15 | Jan 15 – Jan 29 |
| Transplant Outdoors | March 19 | Mar 19 – Apr 2 |
| Direct Sow | March 12 | Mar 12 – Apr 2 |
| Harvest | May 28 | May 28 – Jul 16 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | — |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
256 days in San Augustine County
Growing Tips for Sunflower in San Augustine County
Direct sow Sunflower outdoors after March 05 in San Augustine County when soil has warmed and frost danger has passed.
Sandy soil in San Augustine County dries quickly — mulch Sunflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 96°F in San Augustine County, provide afternoon shade for Sunflower and water deeply in the morning.
Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in San Augustine County, TX?
San Augustine County is in Zone 8b with an average last frost of March 5. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Augustine County, TX?
San Augustine County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 5 and first fall frost is November 16.
Plan Your Garden with Confidence
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