When to Plant Sweet Potatoes in Lamar County, AL
What to do in May
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Lamar County, Alabama.
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Fire up the seed-starting tray: sweet potatoes
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.
Lamar County, Alabama is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 6, giving you a growing season of approximately 228 days.
At an elevation of 69 feet, Lamar County receives approximately 62 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Sweet Potatoes during the growing season. Clay soil retains moisture well for Sweet Potatoes, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.
Lamar County Soil Profile
Soil Type
Clay Loam
Soil pH
5.3-6.7
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 Lamar County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (5.3–6.7) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.
Soil Texture
The clay loam soil in Lamar County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Sweet Potatoes.
How to Plant Sweet Potatoes
Plant Water Budget
Monthly Watering Guide for Sweet Potatoes
Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sweet Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.7" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| May | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.9" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Nov | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Lamar County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Potatoes 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.
Sweet Potatoes Planting Timeline — Lamar County, AL
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 2 | Feb 2 – Feb 16 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Harvest | July 6 | Jul 6 – Aug 24 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
228 days in Lamar County
Growing Tips for Sweet Potatoes in Lamar County
Direct sow Sweet Potatoes outdoors after March 23 in Lamar County when soil has warmed and frost danger has passed.
With Lamar County's clay soil (28% clay), work in 3-4 inches of compost before planting Sweet Potatoes. Avoid tilling when soil is wet to prevent compaction.
General growing tips
Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Lamar County, AL?
Lamar County is in Zone 8a with an average last frost of March 23. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lamar County, AL?
Lamar County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 6.
Your Lamar County Garden Planner — Free
A 24-page printable planner built for Lamar County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.