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When to Plant Cumin in Smith County, TN

Smith County, Tennessee Zone 7b May

Top priorities for Smith County, Tennessee gardeners in May

May is a pivotal month for Smith County, Tennessee gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 10
Avg. first frost October 28
Soil temp (4") 57°F
Watering Moderate
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: cumin

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

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Cumin is a warm-season annual herb whose seeds are one of the most widely used spices globally. It requires a long, hot growing season of 3-4 months.

Smith County, Tennessee is in USDA Zone 7b. The average last spring frost is April 10 and the first fall frost is October 28, giving you a growing season of approximately 201 days.

At an elevation of 3,829 feet, Smith County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Cumin during the growing season.

Smith County, TN (Zone 7b) Long season
201 days
Last Spring Frost April 10
201 growing days
First Fall Frost October 28

Smith County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Start indoors: Mar 1 Transplant: Mar 29 🍅 Harvest: Jul 12 – Sep 13
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Mar 6 Transplant: Apr 3 🍅 Harvest: Jul 17 – Sep 18
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Mar 17 Transplant: Apr 14 🍅 Harvest: Jul 28 – Sep 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 Smith County

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

Soil pH

Your soil pH (5.5–7.0) overlaps with Cumin's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Cumin.

How to Plant Cumin

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

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

Monthly Watering Guide for Cumin

Cumin 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 Cumin Needs Rainfall You Supplement Action
Jan 3.5" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 3" 0" ✅ Rainfall sufficient
Jun 2.2" 3.3" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 3.7" 0" ❄️ Dormant
Dec 3.4" 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.

Cumin 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.

Cumin needs ~2,255 GDD — county provides 4,120 GDD Excellent fit

Cumin Planting Timeline — Smith County, TN

Cumin Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 27 Mar 27 – Apr 17
Harvest July 17 Jul 17 – Sep 18
Fall Sowing August 19 Aug 19 – Sep 2

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June
July Harvest
August Fall Sowing Harvest
September Fall Sowing Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

201 days in Smith County

Growing Tips for Cumin in Smith County

Direct sow Cumin outdoors after April 10 in Smith County when soil has warmed and frost danger has passed.

Common pests for Cumin in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 4 weeks before last frost. Transplant after all danger of frost. Harvest when seed heads turn brown. Requires consistent warmth for proper seed development.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cumin in Smith County, TN?

Smith County is in Zone 7b with an average last frost of April 10. Plan your Cumin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Smith County, TN?

Smith County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 10 and first fall frost is October 28.

🌱

Your Smith County Garden Planner — Free

A 24-page printable planner built for Smith 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.

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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 Smith 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.