Blog

When to Plant Zucchini in Carter County, TN

Carter County, Tennessee Zone 7b May

May in Carter County, Tennessee — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Carter County, Tennessee.

Avg. last frost April 16
Avg. first frost October 22
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 13.9 hrs
  1. Sow zucchini in trays indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Looking ahead to June
  • First harvests: zucchini

Instant PDF download. No spam, unsubscribe any time.

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Carter County, Tennessee is in USDA Zone 7b. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.

At an elevation of 3,776 feet, Carter County receives approximately 53.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Zucchini during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Zucchini root diseases.

Carter County, TN (Zone 7b) Moderate season
189 days
Last Spring Frost April 16
189 growing days
First Fall Frost October 22
Share this guide:

Carter County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Mar 11 Transplant: Apr 22 🍅 Harvest: Jun 10 – Aug 5
Recommended (50%) ✓ Fits season (70 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: Jun 18 – Aug 13
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Jul 4 – Aug 29

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 Carter County

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

Soil pH

Your soil pH (5.6–7.0) overlaps with Zucchini's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Zucchini.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Zucchini.

How to Plant Zucchini

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Zucchini

5
successive plantings in your 189-day season

Sow every 5.1 weeks. Last sowing by Aug 23 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan 4.8" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 5.2" 0" ❄️ Dormant
Apr 5.2" 4.5" 0.7" 💧 Light watering
May 5.2" 4.5" 0.7" 💧 Light watering
Jun 5.2" 4.5" 0.7" 💧 Light watering
Jul 5.2" 5.1" 0.1" 💧 Light watering
Aug 5.2" 5.6" 0" ✅ Rainfall sufficient
Sep 5.2" 4.6" 0.6" 💧 Light watering
Oct 5.2" 3.2" 2" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Carter County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Zucchini 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.

Zucchini needs ~958 GDD — county provides 3,449 GDD Excellent fit

Zucchini Planting Timeline — Carter County, TN

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 23 Apr 23 – May 14
Harvest June 18 Jun 18 – Aug 13

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · Natural rainfall sufficient

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

189 days in Carter County

Growing Tips for Zucchini in Carter County

Direct sow Zucchini outdoors after April 16 in Carter County when soil has warmed and frost danger has passed.

Your generous 189.0-day season in Carter County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.

Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Carter County, TN?

Carter County is in Zone 7b with an average last frost of April 16. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carter County, TN?

Carter County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 16 and first fall frost is October 22.

🌱

Your Carter County Garden Planner — Free

A 24-page printable planner built for Carter 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 Carter County, TN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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