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When to Plant Marigolds in USDA Zone 10b

Zone 10b Zone 10b May

This month in Zone 10b

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 10b.

Avg. last frost February 13
Avg. first frost November 27
  1. Start harvesting marigolds

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

Coming up in June — start thinking about
  • First harvests: marigolds
Get the full Zone 10b Garden Planner — free →

Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

In Zone 10b, the average last spring frost is around January 1 and the first fall frost is around December 31, giving you a growing season of approximately 364 days.

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Zone 10b Year-round
364 days
Last Spring Frost January 1
364 growing days
First Fall Frost December 31

Marigolds Planting Timeline — Zone 10b

Where Is USDA Zone 10b?

The map below highlights the states that contain Zone 10b. Click any state to see the Marigolds planting schedule for that location.

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

Marigolds Planting Calendar — Zone 10b

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors November 20 Nov 20 – Dec 4
Direct Sow November 20 Nov 20 – Dec 11
Harvest January 15 Jan 15 – Aug 13

Plant 0.3" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Free Zone 10b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 10b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

Days to Maturity

50–70 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

364 days (Zone average)

Planting Specifications

Planting Depth0.3 inches
Plant Spacing10 inches apart
Row Spacing12 inches between rows

Succession Planting Marigolds in Zone

8
successive plantings in Zone 's ~364-day season

Sow every 5.7 weeks for continuous harvest throughout the season.

Growing Tips for Marigolds in Zone

Zone has a short growing season (~364 days). Start Marigolds indoors early and use season-extension techniques like row covers and cold frames.

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Cabbage
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Saving Marigolds Seeds

🌾 Save Your Own Marigolds Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower heads dry on plant. Pull dried petals to reveal seeds.
Storage Store in envelopes; viable 3 years at 35°F, under 50% humidity.

Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.

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 Marigolds in Zone 10b?

In Zone 10b, plan your Marigolds planting around the average last frost date of January 1. Start seeds indoors around January 29. Direct sow outdoors around November 20. Transplant seedlings around November 20.

Can Marigolds grow in Zone 10b?

Yes, Marigolds can grow well in Zone 10b, hardy in USDA zones 2a through 11b. Zone 10b has a growing season of approximately 364 days, which is sufficient for Marigolds (50-70 days to maturity).

When can I harvest Marigolds in Zone 10b?

In Zone 10b, expect to harvest Marigolds from January 15 – August 13. Marigolds takes 50-70 days from planting to harvest.

What is the last frost date for Zone 10b?

The average last spring frost in Zone 10b is around January 1, and the first fall frost is around December 31. This gives a growing season of approximately 364 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Marigolds?

Good companion plants for Marigolds include Tomatoes, Peppers, Basil, Squash. 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.

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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.