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When to Plant Zucchini in Bonneville County, ID

Bonneville County, Idaho Zone 5a April

Bonneville County, Idaho gardeners: here's your April plan

If you only do a handful of things in the garden this April, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 26
Avg. first frost September 19
Soil temp (4") 21°F
Watering High
Pest pressure Low
Daylight 13.2 hrs

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Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Bonneville County, Idaho is in USDA Zone 5a. The average last spring frost is May 26 and the first fall frost is September 19, giving you a growing season of approximately 116 days.

At an elevation of 7,993 feet, Bonneville County receives approximately 20.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Zucchini during the growing season.

Bonneville County, ID (Zone 5a) Short season
116 days
Last Spring Frost May 26
116 growing days
First Fall Frost September 19
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Bonneville County Soil Profile

Soil Type

Loam

Soil pH

6.5-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 8 Transplant: May 27 🍅 Harvest: Jul 15 – Sep 9
Recommended (50%) ✗ May not fit
Start indoors: Apr 21 Transplant: Jun 9 🍅 Harvest: Jul 28 – Sep 22
Safe Start (90%) ✗ May not fit
Start indoors: May 17 Transplant: Jul 5 🍅 Harvest: Aug 23 – Oct 18

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 Bonneville County

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

Soil pH

Your soil pH (6.5–8.0) overlaps with Zucchini's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Zucchini.

How to Plant Zucchini

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

Succession Planting Zucchini

2
successive plantings in your 116-day season

Sow every 5.1 weeks. Last sowing by Jul 21 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 549 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 5.2" 2.2" 3" 🚿 Regular watering
Jun 5.2" 1.7" 3.5" 🚿 Regular watering
Jul 5.2" 2.1" 3.1" 🚿 Regular watering
Aug 5.2" 1.9" 3.3" 🚿 Regular watering
Sep 5.2" 1.7" 3.5" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

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

Zucchini 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.

Zucchini needs ~722 GDD — county provides 1,595 GDD Excellent fit

Zucchini Planting Timeline — Bonneville County, ID

Zucchini Planting Calendar

Activity When Date Range
Start Indoors April 21 Apr 21 – May 5
Transplant Outdoors June 9 Jun 9 – Jun 23
Direct Sow June 2 Jun 2 – Jun 23
Harvest July 28 Jul 28 – Sep 22

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

116 days in Bonneville County

Growing Tips for Zucchini in Bonneville County

Direct sow Zucchini outdoors after May 26 in Bonneville County when soil has warmed and frost danger has passed.

Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

Bonneville County receives only 21" of rain annually. Zucchini needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Recommended Zucchini Varieties for Bonneville County

Quick-producing varieties for shorter seasons

Black Beauty (50d) Raven (48d) Eight Ball (40d)

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Bonneville County, ID?

Bonneville County is in Zone 5a with an average last frost of May 26. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bonneville County, ID?

Bonneville County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 26 and first fall frost is September 19.

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Your Bonneville County Garden Planner — Free

A 24-page printable planner built for Bonneville County (Zone 5a). 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 Bonneville County, ID. Local conditions may vary. Last updated: April 2026.

Sources & credits

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