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When to plant Sweet Pea in Pine County County,

Pine County County sits in cold Zone 4a. Plant Sweet Pea April 5–April 26 for the single annual harvest; the September 29 first frost closes the window.

When to Plant Sweet Pea in Pine County, MN

Pine County, Minnesota Zone 4a June

June in the garden — Pine County, Minnesota

A quick June briefing for Pine County, Minnesota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 10
Avg. first frost September 29
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 15.5 hrs
  1. Start sweet pea under lights

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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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.

Pine County, Minnesota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is September 29, giving you a growing season of approximately 142 days.

At an elevation of 538 feet, Pine County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°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
Pine County, MN (Zone 4a) Short season
142 days
Last Spring Frost May 10
142 growing days
First Fall Frost September 29

Pine County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Mar 12 Transplant: Apr 30 🌸 Bloom: Jul 23 – Sep 3
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 22 Transplant: May 10 🌸 Bloom: Aug 2 – Sep 13
Safe Start (90%) ✓ Fits season (20 days to spare)
Start indoors: Apr 2 Transplant: May 21 🌸 Bloom: Aug 13 – Sep 24

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 Pine County

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

Soil pH

Your soil pH (6.0–7.3) is more acidic than Sweet Pea prefers (7.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Pine 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 142-day season

Sow every 7.4 weeks. Last sowing by Jul 06 to harvest before frost.

Sweet Pea 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 15 gal / 100 sq ft

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 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 2.3" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Pine 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 ~975 GDD — county provides 1,846 GDD Excellent fit

Sweet Pea Planting Timeline — Pine County, MN

Sweet Pea Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 5 Apr 5 – Apr 26
Bloom August 2 Aug 2 – Sep 13

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4a

📆 Growing Season

142 days in Pine County

Growing Tips for Sweet Pea in Pine County

Direct sow Sweet Pea outdoors after May 10 in Pine 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 Pine County, MN?

Pine County is in Zone 4a with an average last frost of May 10. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pine County, MN?

Pine County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is September 29.

When should I plant Sweet Pea in Pine County, ?

In Pine County, , plant Sweet Pea after the last frost (around May 10) and before the first frost (around September 29). Best results when soil holds above 50°F.

What growing zone is Pine County, for Sweet Pea?

Pine 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 Pine County's climate?

Yes — Sweet Pea grows well in Pine County's temperate climate. Pine County averages a 142-day frost-free season, with last frost around May 10 and first frost around September 29.

🌱

Your Pine County Garden Planner — Free

A 22-page printable planner built for Pine 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 Pine 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.