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When to plant Sweet Pea in Morrison County County,

Aim to plant Sweet Pea in Morrison County County on or after March 30; the window stays open through April 20. Morrison County County's 155-day frost-free season gives you a single solid spring crop with a brief fall option.

When to Plant Sweet Pea in Morrison County, MN

Morrison County, Minnesota Zone 4a June

This month in Morrison County, Minnesota

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

Avg. last frost May 4
Avg. first frost October 6
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 15.5 hrs
  1. Get sweet pea seeds going inside

    You're about 16 weeks out from your last frost — the perfect window to get these germinating indoors.

Before July arrives, get these ready
  • First harvests: sweet pea

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Sweet peas (Lathyrus odoratus) are beloved cool-season climbing annuals grown primarily for their intensely fragrant, ruffled blooms in shades of pink, purple, red, and white. They thrive in cool spring conditions, climbing trellises to 4–6 feet, and make outstanding cut flowers. Bloom ceases once summer heat arrives, making early sowing critical for a long cutting season.

Morrison County, Minnesota is in USDA Zone 4a. The average last spring frost is May 4 and the first fall frost is October 6, giving you a growing season of approximately 155 days.

At an elevation of 1,070 feet, Morrison County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Sweet Pea to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Good for cutting Fragrant
Morrison County, MN (Zone 4a) Moderate season
155 days
Last Spring Frost May 4
155 growing days
First Fall Frost October 6

Morrison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Mar 9 Transplant: Apr 27 🌸 Bloom: Jul 20 – Aug 31
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 16 Transplant: May 4 🌸 Bloom: Jul 27 – Sep 7
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Apr 1 Transplant: May 20 🌸 Bloom: Aug 12 – 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 Morrison County

How your county's soil matches Sweet Pea's growing requirements.

Soil pH

Your soil pH (5.7–7.1) is more acidic than Sweet Pea prefers (7.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

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

How to Plant Sweet Pea

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Succession Planting Sweet Pea

2
successive plantings in your 155-day season

Sow every 7.4 weeks. Last sowing by Jul 13 to harvest before frost.

Sweet Pea Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/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 Sweet Pea

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

Month Sweet Pea Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Sweet Pea 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.

Sweet Pea needs ~750 GDD — county provides 1,550 GDD Excellent fit

Sweet Pea Planting Timeline — Morrison County, MN

Sweet Pea Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors May 4 May 4 – May 18
Direct Sow March 30 Mar 30 – Apr 20
Bloom July 27 Jul 27 – Sep 7

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4a

📆 Growing Season

155 days in Morrison County

Growing Tips for Sweet Pea in Morrison County

Direct sow Sweet Pea outdoors after May 04 in Morrison County when soil has warmed and frost danger has passed.

Common pests for Sweet Pea in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Soak seeds 24 hours before sowing to soften the hard seed coat; nick the seed coat with a file for the fastest germination. In cold zones (2–6), direct-sow as soon as soil can be worked, 4–6 weeks before last frost; seedlings tolerate light frost but not a hard freeze. In zones 7–9, fall-sow 8–10 weeks before first frost for earlier, stronger spring bloom. Provide a trellis or netting from the start. Feed with low-nitrogen, high-potassium fertilizer once buds form. Pick blooms regularly — even one mature seed pod stops flower production. All plant parts are mildly toxic if eaten.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Pea in Morrison County, MN?

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

What planting zone is Morrison County, MN?

Morrison County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 4 and first fall frost is October 6.

When should I plant Sweet Pea in Morrison County, ?

In Morrison County, , plant Sweet Pea after the last frost (around May 4) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Morrison County, for Sweet Pea?

Morrison County sits in USDA Zone 4a. Sweet Pea grows reliably in zones 2a through 9b, so it's a good fit here.

Can Sweet Pea grow in Morrison County's climate?

Yes — Sweet Pea grows well in Morrison County's temperate climate. Morrison County averages a 155-day frost-free season, with last frost around May 4 and first frost around October 6.

🌱

Your Morrison County Garden Planner — Free

A 22-page printable planner built for Morrison 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 Morrison 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.