Blog

When to Plant Sunflower in Montgomery 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.

Montgomery County, Texas is in USDA Zone 8b. The average last spring frost is February 18 and the first fall frost is December 1, giving you a growing season of approximately 286 days.

At an elevation of 180 feet, Montgomery County receives approximately 62.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96ยฐF, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Montgomery County, TX (Zone 8b) Year-round
286 days
Last Spring Frost February 18
286 growing days
First Fall Frost December 1

Montgomery County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (154 days to spare)
Start indoors: Dec 23 Transplant: Feb 24 🍅 Harvest: May 5 – Jun 23
Recommended (50%) ✓ Fits season (153 days to spare)
Start indoors: Dec 31 Transplant: Mar 4 🍅 Harvest: May 13 – Jul 1
Safe Start (90%) ✓ Fits season (150 days to spare)
Start indoors: Jan 19 Transplant: Mar 23 🍅 Harvest: Jun 1 – Jul 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunflower needs ~1,870 GDD — county provides 6,314 GDD Excellent fit

Sunflower Planting Timeline โ€” Montgomery County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors December 31 Dec 31 โ€“ Jan 14
Transplant Outdoors March 4 Mar 4 โ€“ Mar 18
Direct Sow February 25 Feb 25 โ€“ Mar 18
Harvest May 13 May 13 โ€“ Jul 1

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
May Harvest
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December Start Indoors

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 8b

Growing Season

286 days

Growing Tips for Montgomery County

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

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunflower in Montgomery County, TX?

Montgomery County is in Zone 8b with an average last frost of February 18. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montgomery County, TX?

Montgomery County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is February 18 and first fall frost is December 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montgomery County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Montgomery County, TX. Local conditions may vary. Last updated: April 2026.