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When to Plant Sweet Pea in Uintah County, UT

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.

Uintah County, Utah is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 6,372 feet, Uintah County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 85°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
Uintah County, UT (Zone 5b) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4

Uintah County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

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 0.9" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 1.2" 3.1" 🚿 Regular watering
Aug 4.3" 1.2" 3.1" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

Sweet Pea Planting Timeline — Uintah County, UT

Sweet Pea Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 5 Apr 5 – Apr 26
Bloom July 26 Jul 26 – Sep 27

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 Bloom
August Bloom
September Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

147 days in Uintah County

Growing Tips for Uintah County

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 Uintah County, UT?

Uintah County is in Zone 5b 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 Uintah County, UT?

Uintah County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 4.

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Your Uintah County Garden Planner — Free

A 22-page printable planner built for Uintah County (Zone 5b). 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 Uintah 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.