Blog

When to Plant Sunflower in Dickson County, TN

Dickson County, Tennessee Zone 7b August

Your August game plan for Dickson County, Tennessee

We've pulled the most time-sensitive tasks for Dickson County, Tennessee this August and put them front and centre. Tackle them in order.

Avg. last frost April 4
Avg. first frost October 29
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Harvest sunflower as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this August that'll pay off in September
  • First harvests: sunflower

Instant PDF download. No spam, unsubscribe any time.

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.

Dickson County, Tennessee is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is October 29, giving you a growing season of approximately 208 days.

At an elevation of 2,147 feet, Dickson County receives approximately 54 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Sunflower during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Dickson County, TN (Zone 7b) Long season
208 days
Last Spring Frost April 4
208 growing days
First Fall Frost October 29

Dickson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Mar 7 Transplant: Mar 28 🌸 Bloom: Jun 20 – Oct 10
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Mar 14 Transplant: Apr 4 🌸 Bloom: Jun 27 – Oct 17
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: Mar 28 Transplant: Apr 18 🌸 Bloom: Jul 11 – Oct 31

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 Dickson County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Dickson 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 21 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/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 4.7" 0" ❄️ Dormant
Feb 4.4" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 5.5" 0" ✅ Rainfall sufficient
Jul 2.2" 5.1" 0" ✅ Rainfall sufficient
Aug 2.2" 5.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 4" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dickson 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 ~1,615 GDD — county provides 3,952 GDD Excellent fit

Sunflower Planting Timeline — Dickson County, TN

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow April 4 Apr 4 – Apr 25
Bloom June 27 Jun 27 – Oct 17

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 7b

📆 Growing Season

208 days in Dickson County

Growing Tips for Sunflower in Dickson County

Direct sow Sunflower outdoors after April 04 in Dickson 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 Dickson County, TN?

Dickson County is in Zone 7b with an average last frost of April 4. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dickson County, TN?

Dickson County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is October 29.

🌱

Your Dickson County Garden Planner — Free

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

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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