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When to plant Larkspur in Mower County County,

Plant Larkspur in Mower County County, when soil hits 50°F — usually March 31. Continue planting through April 21 for the spring crop.

When to Plant Larkspur in Mower County, MN

Mower County, Minnesota Zone 4b June

June in Mower County, Minnesota — your action list

Each item below is timed to Mower County, Minnesota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 28
Avg. first frost October 7
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Harvest larkspur as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

To set up a strong July, finish these tasks
  • 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.

Mower County, Minnesota is in USDA Zone 4b. The average last spring frost is April 28 and the first fall frost is October 7, giving you a growing season of approximately 162 days.

At an elevation of 577 feet, Mower County receives approximately 33 inches of rainfall annually with predominantly silt 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
Mower County, MN (Zone 4b) Moderate season
162 days
Last Spring Frost April 28
162 growing days
First Fall Frost October 7
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Mower County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Larkspur Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Transplant: Apr 24 🌸 Bloom: Jul 3 – Aug 21
Recommended (50%) ✓ Fits season (43 days to spare)
Transplant: Apr 28 🌸 Bloom: Jul 7 – Aug 25
Safe Start (90%) ✓ Fits season (36 days to spare)
Transplant: May 14 🌸 Bloom: Jul 23 – Sep 10

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 Mower County

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

Soil pH

Your soil pH (6.3–6.7) is within Larkspur's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — 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 162-day season

Sow every 6.9 weeks. Last sowing by Jul 09 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

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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.2" 3.7" 0" ✅ Rainfall sufficient
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 3.9" 0" ✅ Rainfall sufficient
Jul 2.2" 3.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Mower 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 ~862 GDD — county provides 1,863 GDD Excellent fit

Larkspur Planting Timeline — Mower County, MN

Larkspur Planting Calendar

Activity When Date Range
Direct Sow March 31 Mar 31 – Apr 21
Bloom June 9 Jun 9 – Jul 28

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 4b

📆 Growing Season

162 days in Mower County

Growing Tips for Larkspur in Mower County

Direct sow Larkspur outdoors after April 28 in Mower 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 Mower County, MN?

Mower County is in Zone 4b with an average last frost of April 28. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mower County, MN?

Mower County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 28 and first fall frost is October 7.

When should I plant Larkspur in Mower County, ?

In Mower County, , plant Larkspur after the last frost (around April 28) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Mower County, for Larkspur?

Mower County sits in USDA Zone 4b. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.

Can Larkspur grow in Mower County's climate?

Yes — Larkspur grows well in Mower County's temperate climate. Mower County averages a 162-day frost-free season, with last frost around April 28 and first frost around October 7.

🌱

Your Mower County Garden Planner — Free

A 22-page printable planner built for Mower 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 Mower County, MN. 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.