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When to plant Larkspur in Izard County, AR

Spring Larkspur in Izard County goes in March 4–March 25, once nighttime temps stop dipping near freezing. A second sowing from August 18 to September 1 extends the harvest into fall.

When to Plant Larkspur in Izard County, AR

Izard County, Arkansas Zone 7b August

August in Izard County, Arkansas — your action list

Your garden in Izard County, Arkansas is working on a schedule, even when you're not. Here's where you should be this August.

Avg. last frost April 1
Avg. first frost October 27
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. It's harvest week for larkspur

    If you can't use it all right away, check the food-preservation section of your planner.

  2. Kick off the fall garden with larkspur

    Keep young seedlings shaded and moist in summer heat. A row of taller crops works as natural shade.

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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.

Izard County, Arkansas is in USDA Zone 7b. The average last spring frost is April 1 and the first fall frost is October 27, giving you a growing season of approximately 209 days.

At an elevation of 281 feet, Izard County receives approximately 48.2 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
Izard County, AR (Zone 7b) Long season
209 days
Last Spring Frost April 1
209 growing days
First Fall Frost October 27

Izard County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Larkspur Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Mar 26 🌸 Bloom: Jun 4 – Aug 27
Recommended (50%) ✓ Fits season (55 days to spare)
Transplant: Apr 1 🌸 Bloom: Jun 10 – Sep 2
Safe Start (90%) ✓ Fits season (55 days to spare)
Transplant: Apr 19 🌸 Bloom: Jun 28 – Sep 20

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Izard County

How your county's soil matches Larkspur's growing requirements.

Soil pH

Your soil pH (5.3–6.8) overlaps with Larkspur's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Izard County is excellent for Larkspur — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Larkspur.

How to Plant Larkspur

0.1"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Larkspur

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Larkspur Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Larkspur

Larkspur needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Larkspur Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.8" 0" ✅ Rainfall sufficient
Jul 2.2" 5.6" 0" ✅ Rainfall sufficient
Aug 2.2" 5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 3.4" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

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

Larkspur Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Larkspur needs ~1,200 GDD — county provides 3,344 GDD Excellent fit

Larkspur Planting Timeline — Izard County, AR

Larkspur Planting Calendar

Activity When Date Range
Direct Sow March 4 Mar 4 – Mar 25
Bloom May 13 May 13 – Aug 5
Fall Sowing August 18 Aug 18 – Sep 1

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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

209 days in Izard County

Growing Tips for Larkspur in Izard County

Direct sow Larkspur outdoors after April 01 in Izard County when soil has warmed and frost danger has passed.

General growing tips

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 Izard County, AR?

Izard County is in Zone 7b with an average last frost of April 1. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Izard County, AR?

Izard County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is April 1 and first fall frost is October 27.

When should I plant Larkspur in Izard County, AR?

In Izard County, AR, plant Larkspur after the last frost (around April 1) and before the first frost (around October 27). Best results when soil holds above 50°F.

What growing zone is Izard County, AR for Larkspur?

Izard County sits in USDA Zone 7b. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.

Can Larkspur grow in Izard County's climate?

Yes — Larkspur grows well in Izard County's temperate climate. Izard County averages a 209-day frost-free season, with last frost around April 1 and first frost around October 27.

🌱

Your Izard County Garden Planner — Free

A 22-page printable planner built for Izard 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 Izard County, AR. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.