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When to Plant Larkspur in McClain County, OK

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.

McClain County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 5, giving you a growing season of approximately 217 days.

At an elevation of 558 feet, McClain County receives approximately 23.4 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Larkspur during the growing season.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
McClain County, OK (Zone 7b) Long season
217 days
Last Spring Frost April 2
217 growing days
First Fall Frost November 5

McClain County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

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 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 2.9" 1.4" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 4.3" 1.5" 2.8" 🚿 Regular watering
Nov 4.3" 0.9" 3.4" 🚿 Regular watering
Dec 0.5" 0" ❄️ Dormant

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

Larkspur Planting Timeline — McClain County, OK

Larkspur Planting Calendar

Activity When Date Range
Direct Sow March 5 Mar 5 – Mar 26
Bloom May 14 May 14 – Aug 6
Fall Sowing August 27 Aug 27 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April
May Bloom
June Bloom
July Bloom
August Fall Sowing Bloom
September Fall Sowing
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 7b

📆 Growing Season

217 days in McClain County

Growing Tips for McClain 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 McClain County, OK?

McClain County is in Zone 7b with an average last frost of April 2. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is McClain County, OK?

McClain County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 5.

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Your McClain County Garden Planner — Free

A 22-page printable planner built for McClain County (Zone 7b). 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 McClain County, OK. Local conditions may vary. Last updated: July 2026.

Sources & credits

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