When to Plant Sunflower in Jack County, TX
What to do in June
June is a pivotal month for Jack County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.
-
Harvest sunflower as they ripen
If you can't use it all right away, check the food-preservation section of your planner.
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.
Jack County, Texas is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 9, giving you a growing season of approximately 228 days.
At an elevation of 2,081 feet, Jack County receives approximately 66.9 inches of rainfall annually with predominantly clay soil. Summer highs average 89°F, providing good warmth for Sunflower during the growing season. Clay soil retains moisture well for Sunflower, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
Jack County Soil Profile
Soil Type
Clay
Soil pH
7.3-7.6
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 Jack County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (7.3–7.6) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
Heavy clay soil (42% clay) in Jack County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Drainage
Sunflower prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.
Organic Matter
Organic matter is moderate (3.2%). Annual compost additions will help Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Aug 01 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 | — | 2" | 0" | ❄️ Dormant |
| Feb | — | 2.3" | 0" | ❄️ Dormant |
| Mar | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 9.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 6.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Jack 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 — Jack County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 5 | Mar 5 – Mar 19 |
| Transplant Outdoors | March 19 | Mar 19 – Apr 2 |
| Direct Sow | March 19 | Mar 19 – Apr 9 |
| Bloom | June 11 | Jun 11 – Oct 15 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| 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 8a
📆 Growing Season
228 days in Jack County
Growing Tips for Sunflower in Jack County
Direct sow Sunflower outdoors after March 26 in Jack County when soil has warmed and frost danger has passed.
With Jack County's clay soil (42% clay), work in 3-4 inches of compost before planting Sunflower. Avoid tilling when soil is wet to prevent compaction.
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 Jack County, TX?
Jack County is in Zone 8a with an average last frost of March 26. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jack County, TX?
Jack County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 9.
Your Jack County Garden Planner — Free
A 22-page printable planner built for Jack County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.