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When to Plant Larkspur in USDA Zone 10b

Zone 10b Zone 10b June

June to-do list for Zone 10b

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

Avg. last frost February 13
Avg. first frost November 27
  1. Survive, don't thrive

    June-August is endurance gardening. Keep okra, peppers, sweet potatoes, and southern peas alive. Harvest everything daily before the heat damages produce on the vine.

  2. Start fall tomato seeds indoors

    Yes, indoors — under lights or in AC. They'll be ready to transplant in August when temperatures briefly moderate.

  3. Add compost to empty beds

    Empty beds get a thick layer of compost + mulch to suppress weeds and feed the soil for fall planting.

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Larkspur (Consolida ajacis) is a cool-season annual that produces tall, delicate spires of blue, purple, pink, and white flowers reminiscent of its perennial cousin, delphinium. Direct-sown into cold soil or fall-sown in mild-winter climates, it blooms in spring before going to seed as summer heat arrives. An excellent cut flower and cottage-garden staple.

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.

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

Larkspur 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 Larkspur planting schedule for that location.

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

Larkspur Planting Calendar — Zone 10b

Activity When Date Range
Bloom January 14 Jan 14 – Mar 11
Fall Sowing November 5 Nov 5 – Nov 19

Plant 0.1" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Bloom
February Bloom
March Bloom
April
May
June
July
August
September
October
November Fall Sowing
December

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

60–90 days

Soil pH

6 – 7

Zone Temperature Range

35°F to 40°F average annual minimum

Growing Season

365 days (Zone 10b average)

Planting Specifications

Planting Depth0.1 inches
Plant Spacing8 inches apart
Row Spacing12 inches between rows

Succession Planting Larkspur in Zone 10b

7
successive plantings in Zone 10b's ~365-day season

Sow every 6.9 weeks for continuous harvest throughout the season.

Growing Tips for Larkspur in Zone 10b

Zone 10b offers a long growing season (~365 days). You can plant Larkspur earlier and may get multiple harvests.

Larkspur does not transplant well — direct-sow only. In cold climates (zones 2–6), sow directly in early spring as soon as soil can be worked, 4–6 weeks before last frost; cold soil improves germination. In zones 7–10, fall-sow 8–10 weeks before first frost for spring bloom. Press seeds lightly into soil; they need darkness to germinate — cover with 1/8–1/4 inch of soil. Thin to 6–12 inches to prevent powdery mildew. Allow seed pods to mature and self-sow for naturalized colonies. All parts are toxic if ingested.

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Saving Larkspur 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.

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Frequently Asked Questions

When should I plant Larkspur in Zone 10b?

In Zone 10b, plan your Larkspur planting around the average last frost date of January 1.

Can Larkspur grow in Zone 10b?

Yes, Larkspur can grow well in Zone 10b, hardy in USDA zones 2a through 10b. Zone 10b has a growing season of approximately 364 days, which is sufficient for Larkspur (60-90 days to maturity).

When can I harvest Larkspur in Zone 10b?

In Zone 10b, expect to harvest Larkspur from January 14 – March 11. Larkspur takes 60-90 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 Larkspur?

Good companion plants for Larkspur include Roses, Peonies, Foxglove, Sweet Pea. These companions can help with pest control, pollination, and nutrient sharing.

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