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When to Plant Yam in USDA Zone 9b

Zone 9b Zone 9b May

May in Zone 9b — your action list

Your garden in Zone 9b is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 14
Avg. first frost December 4
Want it on paper? Download your Zone 9b planting guide →

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.

In Zone 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.

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Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Yam Planting Timeline — Zone 9b

Where Is USDA Zone 9b?

The map below highlights the states that contain Zone 9b. Click any state to see the Yam planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Yam Planting Calendar — Zone 9b

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

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

Month-by-Month Timeline

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

Free Zone 9b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

180–330 days

Soil pH

5.5 – 6.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

329 days (Zone average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing6 inches apart
Row Spacing12 inches between rows

Growing Tips for Yam in Zone

Zone has a short growing season (~329 days). Start Yam indoors early and use season-extension techniques like row covers and cold frames.

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

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Saving Yam Seeds

Recommended for Your Garden

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Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Yam in Zone 9b?

In Zone 9b, plan your Yam planting around the average last frost date of January 25. Start seeds indoors around December 14. Direct sow outdoors around January 25. Transplant seedlings around February 1.

Can Yam grow in Zone 9b?

Yes, Yam can grow well in Zone 9b, hardy in USDA zones 9a through 12b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Yam (180-330 days to maturity).

When can I harvest Yam in Zone 9b?

In Zone 9b, expect to harvest Yam from August 2 – November 29. Yam takes 180-330 days from planting to harvest.

What is the last frost date for Zone 9b?

The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Yam?

Good companion plants for Yam include Corn, Green Beans. These companions can help with pest control, pollination, and nutrient sharing.

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Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.