Blog

When to Plant Zucchini in Lyon County, MN

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.

Lyon County, Minnesota is in USDA Zone 4a. The average last spring frost is May 4 and the first fall frost is October 2, giving you a growing season of approximately 151 days.

At an elevation of 634 feet, Lyon County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Zucchini to ensure they mature before fall.

Lyon County, MN (Zone 4a) Moderate season
151 days
Last Spring Frost May 4
151 growing days
First Fall Frost October 2

Lyon County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Mar 17 Transplant: May 19 🍅 Harvest: Jul 7 – Sep 1
Recommended (50%) ✓ Fits season (25 days to spare)
Start indoors: Mar 23 Transplant: May 25 🍅 Harvest: Jul 13 – Sep 7
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: Apr 3 Transplant: Jun 5 🍅 Harvest: Jul 24 – Sep 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 Lyon County

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

Soil pH

Your soil pH (5.8โ€“7.2) overlaps with Zucchini's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) โ€” Zucchini will thrive.

How to Plant Zucchini

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

Succession Planting Zucchini

3
successive plantings in your 151-day season

Sow every 5.1 weeks. Last sowing by Aug 03 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.0″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 271 gal / 100 sq ft

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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.5" 0" โ„๏ธ Dormant
Apr โ€” 3.8" 0" โ„๏ธ Dormant
May 5.2" 4.5" 0.7" ๐Ÿ’ง Light watering
Jun 5.2" 4.1" 1.1" ๐Ÿ’ง Light watering
Jul 5.2" 3.6" 1.6" ๐Ÿ’ง Light watering
Aug 5.2" 3.4" 1.8" ๐Ÿ’ง Light watering
Sep 5.2" 3.2" 2" ๐Ÿ’ง Light watering
Oct 5.2" 2.9" 2.3" ๐Ÿ’ง Light watering
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Lyon County). Supplement amounts are based on average rainfall โ€” 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" 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.

Zucchini needs ~604 GDD — county provides 1,736 GDD Excellent fit

Zucchini Planting Timeline โ€” Lyon County, MN

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors May 25 May 25 โ€“ Jun 8
Direct Sow May 18 May 18 โ€“ Jun 8
Harvest July 13 Jul 13 โ€“ Sep 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

151 days in Lyon County

Growing Tips for Zucchini in Lyon County

Direct sow Zucchini outdoors after May 04 in Lyon County when soil has warmed and frost danger has passed.

Your generous 151.0-day season in Lyon County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.

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.

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.

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 Lyon County, MN?

Lyon County is in Zone 4a with an average last frost of May 4. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lyon County, MN?

Lyon County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 4 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lyon County gardeners in Zone 4a 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 Lyon County, MN. Local conditions may vary. Last updated: April 2026.