When to plant Sunflower in Smith County, KS
In Zone 6a (Smith County), direct-sow Sunflower between April 30 and May 21 for spring, after the April 23 last-frost mark.
When to Plant Sunflower in Smith County, KS
July to-do list for Smith County, Kansas
We've pulled the most time-sensitive tasks for Smith County, Kansas this July and put them front and centre. Tackle them in order.
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Harvest sunflower as they ripen
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
To set up a strong August, finish these tasks
- 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.
Smith County, Kansas is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 14, giving you a growing season of approximately 174 days.
At an elevation of 1,048 feet, Smith County receives approximately 26.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Sunflower to ensure they mature before fall.
Smith County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.3
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 Smith County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.5–7.3) is within Sunflower's preferred range (6.0–7.5).
Soil Texture
The loam soil in Smith County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Sunflower.
Organic Matter
Organic matter is moderate (3.4%). Annual compost additions will help Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jul 06 to harvest before frost.
Sunflower 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 | — | 0.7" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.7" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 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.
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 — Smith County, KS
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 2 | Apr 2 – Apr 16 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Direct Sow | April 30 | Apr 30 – May 21 |
| Bloom | July 23 | Jul 23 – Oct 15 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
174 days in Smith County
Growing Tips for Sunflower in Smith County
Direct sow Sunflower outdoors after April 23 in Smith County when soil has warmed and frost danger has passed.
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 Smith County, KS?
Smith County is in Zone 6a with an average last frost of April 23. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Smith County, KS?
Smith County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 14.
When should I plant Sunflower in Smith County, KS?
In Smith County, KS, plant Sunflower after the last frost (around April 23) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is Smith County, KS for Sunflower?
Smith County sits in USDA Zone 6a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.
Can Sunflower grow in Smith County's climate?
Yes — Sunflower grows well in Smith County's temperate climate. Smith County averages a 174-day frost-free season, with last frost around April 23 and first frost around October 14.
Your Smith County Garden Planner — Free
A 22-page printable planner built for Smith County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.