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When to plant Larkspur in Clinton County County,

Clinton County County gardeners should plant Larkspur between April 2 and April 23 in spring. With Clinton County County's Zone 6a climate (last frost April 30), Larkspur needs 90 days to mature — plant by July 15 for a full harvest.

When to Plant Larkspur in Clinton County, MI

Clinton County, Michigan Zone 6a June

Clinton County, Michigan gardeners: here's your June plan

Your garden in Clinton County, Michigan is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 30
Avg. first frost October 13
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Harvest larkspur as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

July prep starts now
  • First harvests: larkspur

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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.

Clinton County, Michigan is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 13, giving you a growing season of approximately 166 days.

At an elevation of 519 feet, Clinton County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°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
Clinton County, MI (Zone 6a) Moderate season
166 days
Last Spring Frost April 30
166 growing days
First Fall Frost October 13

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Larkspur Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Transplant: Apr 27 🌸 Bloom: Jul 6 – Aug 31
Recommended (50%) ✓ Fits season (40 days to spare)
Transplant: Apr 30 🌸 Bloom: Jul 9 – Sep 3
Safe Start (90%) ✓ Fits season (36 days to spare)
Transplant: May 20 🌸 Bloom: Jul 29 – Sep 23

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 Clinton County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Larkspur's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Larkspur.

Organic Matter

Organic matter is excellent (4.8%) — Larkspur will thrive.

How to Plant Larkspur

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

Succession Planting Larkspur

3
successive plantings in your 166-day season

Sow every 6.9 weeks. Last sowing by Jul 15 to harvest before frost.

Larkspur Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 2.9" 0" ✅ Rainfall sufficient
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clinton 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 ~975 GDD — county provides 2,158 GDD Excellent fit

Larkspur Planting Timeline — Clinton County, MI

Larkspur Planting Calendar

Activity When Date Range
Direct Sow April 2 Apr 2 – Apr 23
Bloom June 11 Jun 11 – Aug 6

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May
June Bloom
July Bloom
August Bloom
September
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 6a

📆 Growing Season

166 days in Clinton County

Growing Tips for Larkspur in Clinton County

Direct sow Larkspur outdoors after April 30 in Clinton 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 Clinton County, MI?

Clinton County is in Zone 6a with an average last frost of April 30. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clinton County, MI?

Clinton County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 13.

When should I plant Larkspur in Clinton County County, ?

In Clinton County County, , plant Larkspur after the last frost (around April 30) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Clinton County County, for Larkspur?

Clinton County 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 Clinton County County's climate?

Yes — Larkspur grows well in Clinton County County's temperate climate. Clinton County County averages a 166-day frost-free season, with last frost around April 30 and first frost around October 13.

🌱

Your Clinton County Garden Planner — Free

A 22-page printable planner built for Clinton 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 Clinton County, MI. 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.