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When to Plant Rhubarb in Utah County, UT

Utah County, Utah Zone 7a May

May in Utah County, Utah — your action list

A quick May briefing for Utah County, Utah gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 5
Avg. first frost October 11
Soil temp (4") 46°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Harden off and plant rhubarb

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

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Rhubarb is a long-lived perennial vegetable grown for its tart, colorful stalks. Only the stalks are edible as the leaves contain toxic oxalic acid.

Utah County, Utah is in USDA Zone 7a. The average last spring frost is May 5 and the first fall frost is October 11, giving you a growing season of approximately 159 days.

At an elevation of 5,535 feet, Utah County receives approximately 22.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Rhubarb during the growing season.

Utah County, UT (Zone 7a) Moderate season
159 days
Last Spring Frost May 5
159 growing days
First Fall Frost October 11
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Utah County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 17
Recommended (50%) ✓ Fits season
Transplant: May 26
Safe Start (90%) ✓ Fits season
Transplant: Jun 21

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 Utah County

How your county's soil matches Rhubarb's growing requirements.

Soil pH

Your soil pH (6.5–8.3) is more alkaline than Rhubarb prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Utah County is excellent for Rhubarb — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Rhubarb.

How to Plant Rhubarb

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 707 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Rhubarb

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

Month Rhubarb Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.5" 1.8" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.4" 1.9" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Rhubarb 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.

Rhubarb needs ~7,939 GDD — county provides 2,305 GDD May not mature

Rhubarb Planting Timeline — Utah County, UT

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors May 26 May 26 – Jun 9

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

159 days in Utah County

Growing Tips for Rhubarb in Utah County

Direct sow Rhubarb outdoors after May 05 in Utah County when soil has warmed and frost danger has passed.

Your 159.0-day growing season in Utah County is tight for Rhubarb (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Utah County receives only 22" of rain annually. Rhubarb needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant crowns in early spring in rich, well-drained soil. Do not harvest stalks the first year. Pull (do not cut) stalks at harvest to avoid introducing rot.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rhubarb in Utah County, UT?

Utah County is in Zone 7a with an average last frost of May 5. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Utah County, UT?

Utah County, Utah is in USDA Hardiness Zone 7a. The average last spring frost is May 5 and first fall frost is October 11.

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Your Utah County Garden Planner — Free

A 24-page printable planner built for Utah County (Zone 7a). 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 Utah County, UT. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.