When to Plant Chard in Idaho County, ID
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.
Idaho County, Idaho is in USDA Zone 5a. The average last spring frost is May 29 and the first fall frost is September 20, giving you a growing season of approximately 114 days.
At an elevation of 6,736 feet, Idaho County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Chard to ensure they mature before fall.
Idaho County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Idaho County
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (6.3–7.8) is more alkaline than Chard prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Idaho County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Chard.
How to Plant Chard
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Chard
Sow every 5.7 weeks. Last sowing by Jul 22 to harvest before frost.
For a dedicated fall crop, sow by Jul 12.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | — | 2.5" | 0" | ❄️ Dormant |
| May | 3.5" | 3.1" | 0.4" | 💧 Light watering |
| Jun | 3.5" | 1.8" | 1.7" | 💧 Light watering |
| Jul | 3.5" | 1.8" | 1.7" | 💧 Light watering |
| Aug | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| Sep | 3.5" | 1.9" | 1.6" | 💧 Light watering |
| Oct | — | 2.3" | 0" | ❄️ Dormant |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Idaho 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 Planting Timeline — Idaho County, ID
Chard Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 24 | Apr 24 – May 8 |
| Transplant Outdoors | May 29 | May 29 – Jun 12 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Harvest | July 24 | Jul 24 – Sep 11 |
| Fall Sowing | July 12 | Jul 12 – Jul 26 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| 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: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
114 days in Idaho County
Growing Tips for Chard in Idaho County
Direct sow Chard outdoors after May 29 in Idaho 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
Check more plant combinations with our Companion Planting Checker →
Chard in Other Locations
Frequently Asked Questions
When should I plant Chard in Idaho County, ID?
Idaho County is in Zone 5a with an average last frost of May 29. Plan your Chard planting based on this frost date — see the calendar above for exact timing.
What planting zone is Idaho County, ID?
Idaho County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 29 and first fall frost is September 20.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Idaho County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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