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When to plant Larkspur in Rush County, IN

Larkspur planted in Rush County between March 17 and April 7 matures in 60–90 days — well before the October 21 first frost.

When to Plant Larkspur in Rush County, IN

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.

Rush County, Indiana is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 21, giving you a growing season of approximately 190 days.

At an elevation of 1,033 feet, Rush County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Larkspur during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Rush County, IN (Zone 6a) Moderate season
190 days
Last Spring Frost April 14
190 growing days
First Fall Frost October 21

Rush County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Larkspur Planting Timeline — Rush County, IN

Larkspur Planting Calendar

Activity When Date Range
Direct Sow March 17 Mar 17 – Apr 7
Bloom May 26 May 26 – Jul 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

190 days in Rush County

Growing Tips for Rush County

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.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Larkspur in Rush County, IN?

Rush County is in Zone 6a with an average last frost of April 14. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rush County, IN?

Rush County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 21.

When should I plant Larkspur in Rush County, IN?

In Rush County, IN, plant Larkspur after the last frost (around April 14) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Rush County, IN for Larkspur?

Rush County sits in USDA Zone 6a. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.

Can Larkspur grow in Rush County's climate?

Yes — Larkspur grows well in Rush County's temperate climate. Rush County averages a 190-day frost-free season, with last frost around April 14 and first frost around October 21.

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Your Rush County Garden Planner — Free

A 22-page printable planner built for Rush County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Rush County, IN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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