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When to Plant Yam in Refugio County, TX

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.

Refugio County, Texas is in USDA Zone 9a. The average last spring frost is February 16 and the first fall frost is December 6, giving you a growing season of approximately 293 days.

At an elevation of 1,000 feet, Refugio County receives approximately 68.4 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, so Yam may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yam root diseases.

Refugio County, TX (Zone 9a) Year-round
293 days
Last Spring Frost February 16
293 growing days
First Fall Frost December 6

Refugio County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Dec 22 Transplant: Feb 9 🍅 Harvest: Aug 10 – Dec 7
Recommended (50%) ✗ May not fit
Start indoors: Jan 5 Transplant: Feb 23 🍅 Harvest: Aug 24 – Dec 21
Safe Start (90%) ✓ Fits season (342 days to spare)
Start indoors: Jan 29 Transplant: Mar 19 🍅 Harvest: Sep 17 – Jan 14

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 Refugio County

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

Soil pH

Your soil pH (6.7โ€“7.2) is more alkaline than Yam prefers (5.5โ€“6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Refugio County is excellent for Yam โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.0%). 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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 60 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 โ€” 2" 0" โ„๏ธ Dormant
Feb 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Mar 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Apr 4.3" 8.3" 0" โœ… Rainfall sufficient
May 4.3" 9.2" 0" โœ… Rainfall sufficient
Jun 4.3" 11.3" 0" โœ… Rainfall sufficient
Jul 4.3" 9.3" 0" โœ… Rainfall sufficient
Aug 4.3" 8" 0" โœ… Rainfall sufficient
Sep 4.3" 5.7" 0" โœ… Rainfall sufficient
Oct 4.3" 4.5" 0" โœ… Rainfall sufficient
Nov 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Dec 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Refugio 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 ~6,949 GDD — county provides 8,011 GDD Good fit

Yam Planting Timeline โ€” Refugio County, TX

Yam Planting Calendar

Activity When Date Range
Start Indoors January 5 Jan 5 โ€“ Jan 19
Transplant Outdoors February 23 Feb 23 โ€“ Mar 9
Direct Sow February 16 Feb 16 โ€“ Mar 9
Harvest August 24 Aug 24 โ€“ Dec 21

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 Transplant Outdoors Direct Sow
April โ€”
May โ€”
June โ€”
July โ€”
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

180โ€“330 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

293 days in Refugio County

Growing Tips for Yam in Refugio County

Direct sow Yam outdoors after February 16 in Refugio County when soil has warmed and frost danger has passed.

With summer highs reaching 103ยฐF in Refugio County, provide afternoon shade for Yam and water deeply in the morning.

Your 294.0-day growing season in Refugio 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 Refugio County, TX?

Refugio County is in Zone 9a with an average last frost of February 16. Plan your Yam planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Refugio County, TX?

Refugio County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 16 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Refugio County, TX. Local conditions may vary. Last updated: April 2026.