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When to Plant Corn in USDA Zone 9b

Zone 9b Zone 9b May

Top priorities for Zone 9b gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 14
Avg. first frost December 4
  1. Start harvesting corn

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

June prep starts now
  • First harvests: corn
Get your free Zone 9b 2026 Planting Guide →
Corn

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

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

Corn 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 Corn planting schedule for that location.

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

Corn Planting Calendar — Zone 9b

Activity When Date Range
Direct Sow February 1 Feb 1 – Feb 22
Harvest April 5 Apr 5 – May 31

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

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

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.

Instant PDF download. No spam, unsubscribe any time.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Moderate — regular watering

Days to Maturity

60–100 days

Soil pH

6 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

329 days (Zone average)

Planting Specifications

Planting Depth1 inches
Plant Spacing12 inches apart
Row Spacing36 inches between rows

Succession Planting Corn in Zone

6
successive plantings in Zone 's ~329-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Corn in Zone

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

Corn needs approximately 1.5 inches of water per week during active growth. Adjust watering based on your local rainfall and soil drainage.

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery
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Saving Corn Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

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

🏷️
Garden Plant Markers $6-12

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

Related Plants

Frequently Asked Questions

When should I plant Corn in Zone 9b?

In Zone 9b, plan your Corn planting around the average last frost date of January 25. Direct sow outdoors around February 1.

Can Corn grow in Zone 9b?

Yes, Corn can grow well in Zone 9b, hardy in USDA zones 3a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Corn (60-100 days to maturity).

When can I harvest Corn in Zone 9b?

In Zone 9b, expect to harvest Corn from April 5 – May 31. Corn takes 60-100 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 Corn?

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

🌱

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.

Instant PDF download. No spam, unsubscribe any time.

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.