When to Plant Sunflower in Harrison County, TX
Your June gardening checklist
June is a pivotal month for Harrison County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Pick sunflower
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Before July arrives, get these ready
- First harvests: sunflower
Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.
Harrison County, Texas is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 14, giving you a growing season of approximately 246 days.
At an elevation of 168 feet, Harrison County receives approximately 63.8 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.
Harrison County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.3-6.8
Drainage
Well Drained
Sunflower 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 Harrison County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (5.3–6.8) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
Sandy soil in Harrison County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Sunflower.
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 06 to harvest before frost.
Sunflower Water Budget
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" | 4.4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 11" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 6.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Harrison 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 — Harrison County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 20 | Feb 20 – Mar 6 |
| Transplant Outdoors | February 27 | Feb 27 – Mar 13 |
| Direct Sow | February 27 | Feb 27 – Mar 20 |
| Bloom | May 22 | May 22 – Oct 9 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | — |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| 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
246 days in Harrison County
Growing Tips for Sunflower in Harrison County
Direct sow Sunflower outdoors after March 13 in Harrison County when soil has warmed and frost danger has passed.
Sandy soil in Harrison 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 Harrison 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 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.
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 Harrison County, TX?
Harrison County is in Zone 8b with an average last frost of March 13. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harrison County, TX?
Harrison County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 14.
Your Harrison County Garden Planner — Free
A 22-page printable planner built for Harrison 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.