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When to Plant Sweet Pea in Wasatch County, UT

Wasatch County, Utah Zone 6a June

Your June game plan for Wasatch County, Utah

Your Wasatch County, Utah garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost May 19
Avg. first frost September 26
Soil temp (4") 45°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
  1. Get sweet pea seeds going inside

    These need a head start before your last frost (May 19). Sow into cells now so you're ready to transplant in a few weeks.

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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.

Wasatch County, Utah is in USDA Zone 6a. The average last spring frost is May 19 and the first fall frost is September 26, giving you a growing season of approximately 130 days.

At an elevation of 8,190 feet, Wasatch County receives approximately 16.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Sweet Pea during the growing season. With low rainfall, drip irrigation is essential for growing Sweet Pea successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Spring Pollinator-friendly Good for cutting Fragrant
Wasatch County, UT (Zone 6a) Short season
130 days
Last Spring Frost May 19
130 growing days
First Fall Frost September 26
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Wasatch County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 23 Transplant: May 4 🌸 Bloom: Jul 20 – Sep 28
Recommended (50%) ✗ May not fit
Start indoors: Apr 7 Transplant: May 19 🌸 Bloom: Aug 4 – Oct 13
Safe Start (90%) ✗ May not fit
Start indoors: May 8 Transplant: Jun 19 🌸 Bloom: Sep 4 – Nov 13

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 Wasatch County

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

Soil pH

Your soil pH (6.6–7.6) overlaps with Sweet Pea's range (7.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Sweet Pea.

How to Plant Sweet Pea

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

Succession Planting Sweet Pea

2
successive plantings in your 130-day season

Sow every 7.4 weeks. Last sowing by Jul 03 to harvest before frost.

Sweet Pea Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 644 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.2" 3.1" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wasatch 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 ~1,088 GDD — county provides 1,885 GDD Excellent fit

Sweet Pea Planting Timeline — Wasatch County, UT

Sweet Pea Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow April 14 Apr 14 – May 5
Bloom August 4 Aug 4 – Oct 13

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

130 days in Wasatch County

Growing Tips for Sweet Pea in Wasatch County

Direct sow Sweet Pea outdoors after May 19 in Wasatch 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.

Wasatch County receives only 17" of rain annually. Sweet Pea needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Wasatch County, UT?

Wasatch County is in Zone 6a with an average last frost of May 19. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wasatch County, UT?

Wasatch County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 19 and first fall frost is September 26.

🌱

Your Wasatch County Garden Planner — Free

A 22-page printable planner built for Wasatch 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 Wasatch County, UT. 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.