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When to Plant Larkspur in Java, SD

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.

Java, South Dakota is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 1, giving you a growing season of approximately 144 days.

At an elevation of 1,070 feet, Walworth County receives approximately 30.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Larkspur to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Java, SD (Zone 4b) Short season
144 days
Last Spring Frost May 10
144 growing days
First Fall Frost October 1

Java Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Monthly Watering Guide for Larkspur

Larkspur needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Larkspur Needs Rainfall You Supplement Action
Jan 2.1" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 2.7" 1.6" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Walworth County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Larkspur Planting Timeline — Java, SD

Larkspur Planting Calendar

Activity When Date Range
Direct Sow April 12 Apr 12 – May 3
Bloom June 21 Jun 21 – Aug 9

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June Bloom
July Bloom
August Bloom
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 4b

📆 Growing Season

144 days in Walworth County

Growing Tips for Java

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 →

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Your Walworth County Garden Planner — Free

A 22-page printable planner built for Walworth County (Zone 4b). 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 Walworth County, SD. Local conditions may vary. Last updated: June 2026.