Blog

When to Plant Asparagus in Tooele County, UT

Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.

Tooele County, Utah is in USDA Zone 6a. The average last spring frost is May 1 and the first fall frost is October 17, giving you a growing season of approximately 169 days.

At an elevation of 4,309 feet, Tooele County receives approximately 12.6 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Asparagus during the growing season. With low rainfall, drip irrigation is essential for growing Asparagus successfully. Mulch heavily to conserve soil moisture.

Tooele County, UT (Zone 6a) Moderate season
169 days
Last Spring Frost May 1
169 growing days
First Fall Frost October 17

Tooele County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 9
Recommended (50%) ✓ Fits season
Transplant: May 15
Safe Start (90%) ✓ Fits season
Transplant: Jun 1

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 Tooele County

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

Soil pH

Your soil pH (6.3โ€“7.8) overlaps with Asparagus's range (6.5โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Tooele County is excellent for Asparagus โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Asparagus.

How to Plant Asparagus

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

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.3″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 879 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Asparagus

Asparagus needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Asparagus Needs Rainfall You Supplement Action
Jan โ€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 0.6" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr โ€” 1.3" 0" โ„๏ธ Dormant
May 3.5" 1.5" 2" ๐Ÿšฟ Regular watering
Jun 3.5" 1" 2.5" ๐Ÿšฟ Regular watering
Jul 3.5" 1" 2.5" ๐Ÿšฟ Regular watering
Aug 3.5" 1.4" 2.1" ๐Ÿšฟ Regular watering
Sep 3.5" 1" 2.5" ๐Ÿšฟ Regular watering
Oct 3.5" 1.2" 2.3" ๐Ÿšฟ Regular watering
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Tooele County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Asparagus 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" โ€” every day above 50ยฐF 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.

Asparagus needs ~15,284 GDD — county provides 2,830 GDD May not mature

Asparagus Planting Timeline โ€” Tooele County, UT

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors May 15 May 15 โ€“ May 29

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

730โ€“1095 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

169 days in Tooele County

Growing Tips for Asparagus in Tooele County

Direct sow Asparagus outdoors after May 01 in Tooele County when soil has warmed and frost danger has passed.

Your 169.0-day growing season in Tooele County is tight for Asparagus (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.

Companion Planting

Good Companions

Avoid Planting Near

  • Garlic
  • Onion

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Asparagus in Tooele County, UT?

Tooele County is in Zone 6a with an average last frost of May 1. Plan your Asparagus planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Tooele County, UT?

Tooele County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 1 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Tooele County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Tooele County, UT. Local conditions may vary. Last updated: April 2026.