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When to Plant Chard in Adams County, ID

Adams County, Idaho Zone 5a April

Your April planting checklist for Adams County, Idaho

April is a pivotal month for Adams County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 20
Avg. first frost September 25
Soil temp (4") 24°F
Watering High
Pest pressure Low
Daylight 13.3 hrs
Get ahead of May
  • Transplants going out: chard
  • Direct-sowing: 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.

Adams County, Idaho is in USDA Zone 5a. The average last spring frost is May 20 and the first fall frost is September 25, giving you a growing season of approximately 128 days.

At an elevation of 6,593 feet, Adams County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Chard during the growing season.

Adams County, ID (Zone 5a) Short season
128 days
Last Spring Frost May 20
128 growing days
First Fall Frost September 25
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Adams County Soil Profile

Soil Type

Loam

Soil pH

6.3-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (24 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 30 – Aug 18
Recommended (50%) ✓ Fits season (23 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jul 15 – Sep 2
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: May 19 Transplant: Jun 23 🍅 Harvest: Aug 18 – Oct 6

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 Adams County

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

Soil pH

Your soil pH (6.3–8.0) is more alkaline than Chard prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Chard.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Chard.

How to Plant Chard

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Chard

2
successive plantings in your 128-day season

Sow every 5.7 weeks. Last sowing by Jul 27 to harvest before frost.

For a dedicated fall crop, sow by Jul 17.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 498 gal / 100 sq ft
Drought risk

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

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 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 3.5" 2.6" 0.9" 💧 Light watering
Jun 3.5" 1.4" 2.1" 🚿 Regular watering
Jul 3.5" 2" 1.5" 💧 Light watering
Aug 3.5" 2.1" 1.4" 💧 Light watering
Sep 3.5" 1.7" 1.8" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Adams 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 ~756 GDD — county provides 1,760 GDD Excellent fit

Chard Planting Timeline — Adams County, ID

Chard Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 6 May 6 – May 27
Harvest July 15 Jul 15 – Sep 2
Fall Sowing July 17 Jul 17 – Jul 31

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 Transplant Outdoors
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · 1-2 times/week

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

128 days in Adams County

Growing Tips for Chard in Adams County

Direct sow Chard outdoors after May 20 in Adams 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 Adams County, ID?

Adams County is in Zone 5a with an average last frost of May 20. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, ID?

Adams County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 20 and first fall frost is September 25.

🌱

Your Adams County Garden Planner — Free

A 24-page printable planner built for Adams 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 Adams 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.