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When to Plant Chard in Trempealeau County, WI

Trempealeau County, Wisconsin Zone 4b May

Your May game plan for Trempealeau County, Wisconsin

We've pulled the most time-sensitive tasks for Trempealeau County, Wisconsin this May and put them front and centre. Tackle them in order.

Avg. last frost May 15
Avg. first frost September 30
Soil temp (4") 52°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Time to transplant chard

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Plant chard from seed, right in the garden

    These tolerate cool soil, so you're not gambling by sowing now.

Get ahead of June
  • Starting indoors: chard

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Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

Trempealeau County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 30, giving you a growing season of approximately 138 days.

At an elevation of 1,222 feet, Trempealeau County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Chard to ensure they mature before fall.

Trempealeau County, WI (Zone 4b) Short season
138 days
Last Spring Frost May 15
138 growing days
First Fall Frost September 30

Trempealeau County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Mar 28 Transplant: May 9 🍅 Harvest: Jul 4 – Aug 22
Recommended (50%) ✓ Fits season (33 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Aug 28
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Jul 17 – Sep 4

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 Trempealeau County

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

Soil pH

Your soil pH (5.7–7.2) overlaps with Chard's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Trempealeau County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) — Chard will thrive.

How to Plant Chard

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Chard

3
successive plantings in your 138-day season

Sow every 5.7 weeks. Last sowing by Aug 01 to harvest before frost.

For a dedicated fall crop, sow by Jul 08.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Chard

Chard 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 Chard Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.1" 0" ❄️ Dormant
May 3.5" 4.4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.9" 0" ✅ Rainfall sufficient
Jul 3.5" 4.2" 0" ✅ Rainfall sufficient
Aug 3.5" 4.1" 0" ✅ Rainfall sufficient
Sep 3.5" 3.5" 0" ✅ Rainfall sufficient
Oct 3.6" 0" ❄️ Dormant
Nov 2.7" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Chard 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.

Chard needs ~591 GDD — county provides 1,483 GDD Excellent fit

Chard Planting Timeline — Trempealeau County, WI

Chard Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 10 Jul 10 – Aug 28
Fall Sowing July 8 Jul 8 – Jul 22

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

138 days in Trempealeau County

Growing Tips for Chard in Trempealeau County

Direct sow Chard outdoors after May 15 in Trempealeau County when soil has warmed and frost danger has passed.

General growing tips

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chard in Trempealeau County, WI?

Trempealeau County is in Zone 4b with an average last frost of May 15. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Trempealeau County, WI?

Trempealeau County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 30.

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Your Trempealeau County Garden Planner — Free

A 24-page printable planner built for Trempealeau County (Zone 4b). 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 Trempealeau County, WI. 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.