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When to plant Sunflower in Trigg County, KY

Trigg County's climate puts the Sunflower spring window between April 5 and April 26. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Sunflower in Trigg County, KY

Trigg County, Kentucky Zone 7a June

What to do in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Trigg County, Kentucky.

Avg. last frost April 5
Avg. first frost October 30
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Basket week: sunflower

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July prep starts now
  • First harvests: sunflower

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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.

Trigg County, Kentucky is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is October 30, giving you a growing season of approximately 208 days.

At an elevation of 1,825 feet, Trigg County receives approximately 48.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Trigg County, KY (Zone 7a) Long season
208 days
Last Spring Frost April 5
208 growing days
First Fall Frost October 30

Trigg County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Mar 9 Transplant: Mar 30 🌸 Bloom: Jun 22 – Sep 28
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Mar 15 Transplant: Apr 5 🌸 Bloom: Jun 28 – Oct 4
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Mar 28 Transplant: Apr 18 🌸 Bloom: Jul 11 – Oct 17

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 Trigg County

How your county's soil matches Sunflower's growing requirements.

Soil pH

Your soil pH (5.2–6.8) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Trigg County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Sunflower

3
successive plantings in your 208-day season

Sow every 8 weeks. Last sowing by Jul 22 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 3.7" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 4" 0" ✅ Rainfall sufficient
Jul 2.2" 5.7" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 3.9" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 3.4" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Trigg 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 needs ~1,360 GDD — county provides 3,328 GDD Excellent fit

Sunflower Planting Timeline — Trigg County, KY

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow April 5 Apr 5 – Apr 26
Bloom June 28 Jun 28 – Oct 4

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
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 7a

📆 Growing Season

208 days in Trigg County

Growing Tips for Sunflower in Trigg County

Direct sow Sunflower outdoors after April 05 in Trigg 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

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Trigg County, KY?

Trigg County is in Zone 7a with an average last frost of April 5. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Trigg County, KY?

Trigg County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is October 30.

When should I plant Sunflower in Trigg County, KY?

In Trigg County, KY, plant Sunflower after the last frost (around April 5) and before the first frost (around October 30). Best results when soil holds above 50°F.

What growing zone is Trigg County, KY for Sunflower?

Trigg County sits in USDA Zone 7a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Trigg County's climate?

Yes — Sunflower grows well in Trigg County's temperate climate. Trigg County averages a 208-day frost-free season, with last frost around April 5 and first frost around October 30.

🌱

Your Trigg County Garden Planner — Free

A 22-page printable planner built for Trigg County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.