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When to Plant Yam in Grady County, GA

Grady County, Georgia Zone 9a May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Grady County, Georgia this May and put them front and centre. Tackle them in order.

Avg. last frost March 5
Avg. first frost November 21
Soil temp (4") 73°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs

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True yams are tropical tubers distinct from sweet potatoes, producing large starchy roots that can weigh several pounds. They are a staple food in tropical regions worldwide.

Grady County, Georgia is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 21, giving you a growing season of approximately 261 days.

At an elevation of 323 feet, Grady County receives approximately 48.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, providing good warmth for Yam during the growing season. Clay soil retains moisture well for Yam, but amend with compost to improve drainage and prevent root rot.

Grady County, GA (Zone 9a) Long season
261 days
Last Spring Frost March 5
261 growing days
First Fall Frost November 21
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Grady County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Jan 10 Transplant: Feb 28 🍅 Harvest: Aug 29 – Dec 26
Recommended (50%) ✓ Fits season (318 days to spare)
Start indoors: Jan 22 Transplant: Mar 12 🍅 Harvest: Sep 10 – Jan 7
Safe Start (90%) ✓ Fits season (321 days to spare)
Start indoors: Feb 12 Transplant: Apr 2 🍅 Harvest: Oct 1 – Jan 28

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 Grady County

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

Soil pH

Your soil pH (5.4–6.5) overlaps with Yam's range (5.5–6.5), though not a perfect match.

Soil Texture

The clay loam soil in Grady County is excellent for Yam — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Yam.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Yam.

How to Plant Yam

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Plant Water Budget

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

Monthly Watering Guide for Yam

Yam needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Yam Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 4.9" 0" ✅ Rainfall sufficient
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 5.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 4.3" 3.7" 0.6" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

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

Yam 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.

Yam needs ~4,654 GDD — county provides 4,763 GDD Good fit

Yam Planting Timeline — Grady County, GA

Yam Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors March 12 Mar 12 – Mar 26
Direct Sow March 5 Mar 5 – Mar 26
Harvest September 10 Sep 10 – Jan 7

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

180–330 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

261 days in Grady County

Growing Tips for Yam in Grady County

Direct sow Yam outdoors after March 05 in Grady County when soil has warmed and frost danger has passed.

With Grady County's clay soil (33% clay), work in 3-4 inches of compost before planting Yam. Avoid tilling when soil is wet to prevent compaction.

Your 261.0-day growing season in Grady County is tight for Yam (180.0-330.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant tuber pieces in mounds of loose, rich soil. Provide sturdy trellising for climbing vines. Yams require a long, warm growing season of 8-11 months. Harvest when vines die back.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Yam in Grady County, GA?

Grady County is in Zone 9a with an average last frost of March 5. Plan your Yam planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grady County, GA?

Grady County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 21.

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Your Grady County Garden Planner — Free

A 24-page printable planner built for Grady County (Zone 9a). 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 Grady County, GA. 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.