When to Plant Chard in Bonner 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.
Bonner County, Idaho is in USDA Zone 5b. The average last spring frost is May 5 and the first fall frost is October 3, giving you a growing season of approximately 151 days.
At an elevation of 7,480 feet, Bonner County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Chard during the growing season. With low rainfall, drip irrigation is essential for growing Chard successfully. Mulch heavily to conserve soil moisture.
Bonner County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.2
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.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Chard Planting Timeline — Bonner County, ID
Chard Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 31 | Mar 31 – Apr 14 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Fall Sowing | July 25 | Jul 25 – Aug 8 |
| Harvest | June 30 | Jun 30 – Aug 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
50–60 days
Soil pH
6 – 7
USDA Zone
Zone 5b
Growing Season
151 days
Growing Tips for Bonner County
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
Level Up Your Garden
Chard in Other Locations
Frequently Asked Questions
When should I plant Chard in Bonner County, ID?
Bonner County is in Zone 5b with an average last frost of May 5. Plan your Chard planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bonner County, ID?
Bonner County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 5 and first fall frost is October 3.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Bonner County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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