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When to Plant Nasturtium in USDA Zone 10a

Zone 10a Zone 10a June

What to do in June

A quick June briefing for Zone 10a gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 1
Avg. first frost December 19
  1. Collect nasturtium at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

July prep starts now
  • First harvests: nasturtium
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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 10a, 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.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Zone 10a Year-round
365 days
Last Spring Frost No frost
365 growing days
First Fall Frost No frost

Nasturtium Planting Timeline — Zone 10a

Where Is USDA Zone 10a?

The map below highlights the states that contain Zone 10a. 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 10a

Activity When Date Range
Start Indoors December 4 Dec 4 – Dec 18
Transplant Outdoors November 20 Nov 20 – Dec 4
Direct Sow November 20 Nov 20 – Dec 11
Bloom January 15 Jan 15 – Aug 13

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

Month-by-Month Timeline

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

Free Zone 10a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 10a 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

30°F to 35°F average annual minimum

Growing Season

365 days (Zone 10a average)

Planting Specifications

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

Succession Planting Nasturtium in Zone 10a

8
successive plantings in Zone 10a's ~365-day season

Sow every 6.3 weeks for continuous harvest throughout the season.

Growing Tips for Nasturtium in Zone 10a

Zone 10a offers a long growing season (~365 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 10a?

In Zone 10a, plan your Nasturtium planting around the average last frost date of January 1. Start seeds indoors around December 4. Direct sow outdoors around November 20. Transplant seedlings around November 20.

Can Nasturtium grow in Zone 10a?

Yes, Nasturtium can grow well in Zone 10a, hardy in USDA zones 2a through 11b. Zone 10a has a growing season of approximately 364 days, which is sufficient for Nasturtium (55-65 days to maturity).

When can I harvest Nasturtium in Zone 10a?

In Zone 10a, expect to harvest Nasturtium from January 15 – August 13. Nasturtium takes 55-65 days from planting to harvest.

What is the last frost date for Zone 10a?

The average last spring frost in Zone 10a 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 Nasturtium?

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

🌱

Your Zone 10a Garden Planner — Free

A 22-page printable planner tailored to Zone 10a. 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.