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When to Plant Yam in Pinellas 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.

Pinellas County, Florida is in USDA Zone 9b. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.

At an elevation of 246 feet, Pinellas County receives approximately 58.1 inches of rainfall annually with predominantly sand soil. Summer highs average 102ยฐF, 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.

Pinellas County, FL (Zone 9b) Year-round
325 days
Last Spring Frost January 25
325 growing days
First Fall Frost December 16

Pinellas County Soil Profile

Soil Type

Sand

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Dec 8 Transplant: Jan 26 🍅 Harvest: Jul 27 – Nov 23
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: Aug 2 – Nov 29
Safe Start (90%) ✓ Fits season (356 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: Sep 5 – Jan 2

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 Pinellas County

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

Soil pH

Your soil pH (5.1โ€“6.2) overlaps with Yam's range (5.5โ€“6.5), though not a perfect match.

Soil Texture

Sandy soil in Pinellas 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 (1.5%). 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 1,600 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 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Feb 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Mar 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Apr 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
May 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jun 4.3" 7.6" 0" โœ… Rainfall sufficient
Jul 4.3" 8.5" 0" โœ… Rainfall sufficient
Aug 4.3" 8.7" 0" โœ… Rainfall sufficient
Sep 4.3" 7.1" 0" โœ… Rainfall sufficient
Oct 4.3" 5.3" 0" โœ… Rainfall sufficient
Nov 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Dec 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Janโ€“Dec in Pinellas 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 ~6,758 GDD — county provides 8,639 GDD Good fit

Yam Planting Timeline โ€” Pinellas County, FL

Yam Planting Calendar

Activity When Date Range
Start Indoors December 14 Dec 14 โ€“ Dec 28
Transplant Outdoors February 1 Feb 1 โ€“ Feb 15
Direct Sow January 25 Jan 25 โ€“ Feb 15
Harvest August 2 Aug 2 โ€“ Nov 29

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

Month-by-Month Timeline

MonthActivities
January Direct Sow
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

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 9b

๐Ÿ“† Growing Season

325 days in Pinellas County

Growing Tips for Yam in Pinellas County

Direct sow Yam outdoors after January 25 in Pinellas County when soil has warmed and frost danger has passed.

Sandy soil in Pinellas 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 102ยฐF in Pinellas County, provide afternoon shade for Yam and water deeply in the morning.

Your 326.0-day growing season in Pinellas 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 Pinellas County, FL?

Pinellas County is in Zone 9b with an average last frost of January 25. Plan your Yam planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pinellas County, FL?

Pinellas County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is January 25 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pinellas County gardeners in Zone 9b 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 Pinellas County, FL. Local conditions may vary. Last updated: April 2026.