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When to Plant Yam in Sumter County, FL

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.

Sumter County, Florida is in USDA Zone 9a. The average last spring frost is February 6 and the first fall frost is December 6, giving you a growing season of approximately 303 days.

At an elevation of 463 feet, Sumter County receives approximately 60.9 inches of rainfall annually with predominantly sand soil. Summer highs average 96ยฐF, so Yam may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Sumter County, FL (Zone 9a) Year-round
303 days
Last Spring Frost February 6
303 growing days
First Fall Frost December 6

Sumter County Soil Profile

Soil Type

Sand

Soil pH

5-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Dec 13 Transplant: Jan 31 🍅 Harvest: Aug 1 – Nov 28
Recommended (50%) ✗ May not fit
Start indoors: Dec 26 Transplant: Feb 13 🍅 Harvest: Aug 14 – Dec 11
Safe Start (90%) ✓ Fits season (353 days to spare)
Start indoors: Jan 21 Transplant: Mar 11 🍅 Harvest: Sep 9 – Jan 6

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 Sumter County

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

Soil pH

Your soil pH (5.0โ€“6.1) overlaps with Yam's range (5.5โ€“6.5), though not a perfect match.

Soil Texture

Sandy soil in Sumter 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 (1.4%). Add 2-3 inches of compost before planting 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
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,489 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Mar 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Apr 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
May 4.3" 4.3" 0" โœ… Rainfall sufficient
Jun 4.3" 8" 0" โœ… Rainfall sufficient
Jul 4.3" 8.7" 0" โœ… Rainfall sufficient
Aug 4.3" 8.5" 0" โœ… Rainfall sufficient
Sep 4.3" 7.6" 0" โœ… Rainfall sufficient
Oct 4.3" 6.1" 0" โœ… Rainfall sufficient
Nov 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Dec 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Sumter County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~5,610 GDD — county provides 6,688 GDD Good fit

Yam Planting Timeline โ€” Sumter County, FL

Yam Planting Calendar

Activity When Date Range
Start Indoors December 26 Dec 26 โ€“ Jan 9
Transplant Outdoors February 13 Feb 13 โ€“ Feb 27
Direct Sow February 6 Feb 6 โ€“ Feb 27
Harvest August 14 Aug 14 โ€“ Dec 11

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

180โ€“330 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

303 days in Sumter County

Growing Tips for Yam in Sumter County

Direct sow Yam outdoors after February 06 in Sumter County when soil has warmed and frost danger has passed.

Sandy soil in Sumter County dries quickly โ€” 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 96ยฐF in Sumter County, provide afternoon shade for Yam and water deeply in the morning.

Your 304.0-day growing season in Sumter 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 Sumter County, FL?

Sumter County is in Zone 9a with an average last frost of February 6. Plan your Yam planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sumter County, FL?

Sumter County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 6 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sumter County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Sumter County, FL. Local conditions may vary. Last updated: April 2026.