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When to plant Bleeding Hearts in Cass County County,

In Cass County County, Bleeding Hearts is a spring-only crop. Plant May 26–June 9 once soil hits 50°F.

When to Plant Bleeding Hearts in Cass County, MN

Cass County, Minnesota Zone 4a June

Cass County, Minnesota gardeners: here's your June plan

We've pulled the most time-sensitive tasks for Cass County, Minnesota this June and put them front and centre. Tackle them in order.

Avg. last frost May 12
Avg. first frost September 28
Soil temp (4") 61°F
Watering Low
Pest pressure Moderate
Daylight 15.7 hrs
July will be here before you know it — start on
  • Starting indoors: bleeding hearts
  • First harvests: bleeding hearts

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Bleeding Hearts (Lamprocapnos spectabilis) are elegant woodland perennials producing arching stems hung with distinctive heart-shaped pink or white flowers with protruding inner petals — the "drops" beneath each heart. A beloved heirloom perennial from Asia, bleeding hearts emerge vigorously in spring, bloom prolifically for 4–6 weeks, and then go dormant in summer heat — a natural die-back that is entirely normal. The dormancy gap should be planned for by interplanting with summer-emerging hostas, ferns, or impatiens. Fringed bleeding heart (Dicentra eximia), a US native, has a longer bloom season and does not go fully dormant. All parts are toxic if ingested.

Cass County, Minnesota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 28, giving you a growing season of approximately 139 days.

At an elevation of 938 feet, Cass County receives approximately 32.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Bleeding Hearts to ensure they mature before fall.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Cass County, MN (Zone 4a) Short season
139 days
Last Spring Frost May 12
139 growing days
First Fall Frost September 28
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Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.9

Drainage

Well Drained

Bleeding Hearts Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Feb 27 Transplant: May 22 🌸 Bloom: Jul 17 – Aug 28
Recommended (50%) ✓ Fits season (27 days to spare)
Start indoors: Mar 3 Transplant: May 26 🌸 Bloom: Jul 21 – Sep 1
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: Mar 18 Transplant: Jun 10 🌸 Bloom: Aug 5 – Sep 16

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 Cass County

How your county's soil matches Bleeding Hearts's growing requirements.

Soil pH

Your soil pH (5.9–6.9) overlaps with Bleeding Hearts's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Bleeding Hearts will thrive.

How to Plant Bleeding Hearts

1.5"
Planting Depth
24"
Between Plants
30"
Between Rows

Succession Planting Bleeding Hearts

2
successive plantings in your 139-day season

Sow every 6.9 weeks. Last sowing by Jun 30 to harvest before frost.

Bleeding Hearts Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 26 gal / 100 sq ft

Monthly Watering Guide for Bleeding Hearts

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

Month Bleeding Hearts Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 2.5" 0" ❄️ Dormant
Nov 2.2" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Bleeding Hearts 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.

Bleeding Hearts needs ~750 GDD — county provides 1,390 GDD Excellent fit

Bleeding Hearts Planting Timeline — Cass County, MN

Bleeding Hearts Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors May 26 May 26 – Jun 9
Bloom July 21 Jul 21 – Sep 1

Plant 1.5" deep · 24" apart · Rows 30" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors
June Transplant Outdoors
July Bloom
August Bloom
September Bloom
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

139 days in Cass County

Growing Tips for Bleeding Hearts in Cass County

Direct sow Bleeding Hearts outdoors after May 12 in Cass County when soil has warmed and frost danger has passed.

General growing tips

Plant bare-root crowns in early spring as soon as soil is workable, or in fall at least 6 weeks before hard freeze. Set eyes 1–2 inches below soil level. Morning sun with afternoon shade is ideal; deep shade is tolerated but reduces bloom. Keep moist but well-drained — will not tolerate waterlogged soil. After flowering, the foliage will yellow and die back in summer heat — this is normal. Do not cut back until foliage turns fully yellow; the plant is storing energy. Mark the location to avoid disturbing crowns during summer dormancy. Divide every 4–5 years in early spring. Year 2+ plants produce the fullest flowering display.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bleeding Hearts in Cass County, MN?

Cass County is in Zone 4a with an average last frost of May 12. Plan your Bleeding Hearts planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, MN?

Cass County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 28.

When should I plant Bleeding Hearts in Cass County County, ?

In Cass County County, , plant Bleeding Hearts after the last frost (around May 12) and before the first frost (around September 28). Best results when soil holds above 50°F.

What growing zone is Cass County County, for Bleeding Hearts?

Cass County County sits in USDA Zone 4a. Bleeding Hearts grows reliably in zones 3a through 9a, so it's a good fit here.

Can Bleeding Hearts grow in Cass County County's climate?

Yes — Bleeding Hearts grows well in Cass County County's temperate climate. Cass County County averages a 139-day frost-free season, with last frost around May 12 and first frost around September 28.

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Your Cass County Garden Planner — Free

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

Sources & credits

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