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When to Plant Nasturtium in USDA Zone 9b

Zone 9b Zone 9b June

Top priorities for Zone 9b gardeners in June

June is a pivotal month for Zone 9b gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 14
Avg. first frost December 4
  1. Basket week: nasturtium

    If you can't use it all right away, check the food-preservation section of your planner.

Looking ahead to July
  • First harvests: nasturtium
Download your personalised Zone 9b planting plan →

Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.

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.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
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Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Nasturtium 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 Nasturtium planting schedule for that location.

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

Nasturtium Planting Calendar — Zone 9b

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors December 28 Dec 28 – Jan 11
Direct Sow December 28 Dec 28 – Jan 18
Bloom February 22 Feb 22 – Sep 6

Plant 0.5" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

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

Low — drought tolerant

Days to Maturity

55–65 days

Soil pH

6 – 8

Zone Temperature Range

25°F to 30°F average annual minimum

Growing Season

329 days (Zone 9b average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing10 inches apart
Row Spacing12 inches between rows

Succession Planting Nasturtium in Zone 9b

7
successive plantings in Zone 9b's ~329-day season

Sow every 6.3 weeks for continuous harvest throughout the season.

Growing Tips for Nasturtium in Zone 9b

Zone 9b offers a long growing season (~329 days). You can plant Nasturtium earlier and may get multiple harvests.

Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
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Saving Nasturtium Seeds

Recommended for Your Garden

☀️
Garden Shade Cloth $15-35

Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.

🌱
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.

Related Plants

Frequently Asked Questions

When should I plant Nasturtium in Zone 9b?

In Zone 9b, plan your Nasturtium planting around the average last frost date of January 25. Start seeds indoors around December 28. Direct sow outdoors around December 28. Transplant seedlings around December 28.

Can Nasturtium grow in Zone 9b?

Yes, Nasturtium can grow well in Zone 9b, hardy in USDA zones 2a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Nasturtium (55-65 days to maturity).

When can I harvest Nasturtium in Zone 9b?

In Zone 9b, expect to harvest Nasturtium from February 22 – September 6. Nasturtium takes 55-65 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 Nasturtium?

Good companion plants for Nasturtium include Tomatoes, Cucumbers, Squash, Radishes. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Zone 9b Garden Planner — Free

A 22-page printable planner tailored to Zone 9b. 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: June 2026.

Sources & credits

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