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When to Plant Hardy Kiwi in Box Elder County, UT

Box Elder County, Utah Zone 6b May

What to do in May

Each item below is timed to Box Elder County, Utah's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 22
Avg. first frost October 3
Soil temp (4") 50°F
Watering High
Pest pressure Low
Daylight 14.3 hrs
June prep starts now
  • Transplants going out: hardy kiwi

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Hardy kiwi produces grape-sized, smooth-skinned fruits eaten whole without peeling. Unlike fuzzy kiwi, it is extremely cold-hardy to -25F once established.

Box Elder County, Utah is in USDA Zone 6b. The average last spring frost is May 22 and the first fall frost is October 3, giving you a growing season of approximately 134 days.

At an elevation of 4,039 feet, Box Elder County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Hardy Kiwi during the growing season.

Box Elder County, UT (Zone 6b) Short season
134 days
Last Spring Frost May 22
134 growing days
First Fall Frost October 3
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Box Elder County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 2
Recommended (50%) ✓ Fits season
Transplant: Jun 12
Safe Start (90%) ✓ Fits season
Transplant: Jul 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 Box Elder County

How your county's soil matches Hardy Kiwi's growing requirements.

Soil pH

Your soil pH (6.3–7.9) is more alkaline than Hardy Kiwi prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Box Elder County is excellent for Hardy Kiwi — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Hardy Kiwi.

How to Plant Hardy Kiwi

72"
Between Plants
96"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 332 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Hardy Kiwi

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

Month Hardy Kiwi Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 4.3" 2.4" 1.9" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 2.4" 1.9" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 1.7" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Hardy Kiwi 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.

Hardy Kiwi needs ~22,265 GDD — county provides 2,043 GDD May not mature

Hardy Kiwi Planting Timeline — Box Elder County, UT

Hardy Kiwi Planting Calendar

Activity When Date Range
Transplant Outdoors June 12 Jun 12 – Jun 26

· 72" apart · Rows 96" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

1095–1825 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

134 days in Box Elder County

Growing Tips for Hardy Kiwi in Box Elder County

Direct sow Hardy Kiwi outdoors after May 22 in Box Elder County when soil has warmed and frost danger has passed.

Your 134.0-day growing season in Box Elder County is tight for Hardy Kiwi (1095.0-1825.0 days to maturity). Start indoors and choose early-maturing varieties.

Box Elder County receives only 24" of rain annually. Hardy Kiwi needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant male and female vines for pollination. Provide very strong trellising as vines become massive. Prune similarly to grapes. Protect young plants from late spring frost.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hardy Kiwi in Box Elder County, UT?

Box Elder County is in Zone 6b with an average last frost of May 22. Plan your Hardy Kiwi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Box Elder County, UT?

Box Elder County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is May 22 and first fall frost is October 3.

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Your Box Elder County Garden Planner — Free

A 24-page printable planner built for Box Elder County (Zone 6b). 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 Box Elder 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.