When to Plant Yam in Glynn County, GA
May in Glynn County, Georgia — your action list
Your garden in Glynn County, Georgia is working on a schedule, even when you're not. Here's where you should be this May.
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.
Glynn County, Georgia is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 13, giving you a growing season of approximately 307 days.
At an elevation of 135 feet, Glynn County receives approximately 55.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Yam may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Yam will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yam root diseases.
Glynn County Soil Profile
Soil Type
Sandy Loam
Soil pH
4.9-6.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Glynn County
How your county's soil matches Yam's growing requirements.
Soil pH
Your soil pH (4.9–6.2) overlaps with Yam's range (5.5–6.5), though not a perfect match.
Soil Texture
Sandy soil in Glynn County warms quickly in spring but drains fast. Yam will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Yam.
Organic Matter
Organic matter is low (1.8%). Add 2-3 inches of compost before planting Yam.
How to Plant Yam
Plant Water Budget
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 | — | 4.4" | 0" | ❄️ Dormant |
| Feb | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Mar | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 5.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Dec | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Glynn 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 Planting Timeline — Glynn County, GA
Yam Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 29 | Dec 29 – Jan 12 |
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Direct Sow | February 9 | Feb 9 – Mar 2 |
| Harvest | August 17 | Aug 17 – Dec 14 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Start Indoors Harvest |
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
307 days in Glynn County
Growing Tips for Yam in Glynn County
Direct sow Yam outdoors after February 09 in Glynn County when soil has warmed and frost danger has passed.
Sandy soil in Glynn County dries quickly — mulch Yam with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 97°F in Glynn County, provide afternoon shade for Yam and water deeply in the morning.
Your 308.0-day growing season in Glynn 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 →
Yam in Other Locations
Frequently Asked Questions
When should I plant Yam in Glynn County, GA?
Glynn County is in Zone 9a with an average last frost of February 9. Plan your Yam planting based on this frost date — see the calendar above for exact timing.
What planting zone is Glynn County, GA?
Glynn County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 13.
Your Glynn County Garden Planner — Free
A 24-page printable planner built for Glynn 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.