When to Plant Basil in Valley County, ID
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
Valley County, Idaho is in USDA Zone 4b. The average last spring frost is June 18 and the first fall frost is September 3, giving you a growing season of approximately 77 days.
At an elevation of 7,884 feet, Valley County receives approximately 17.8 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Basil to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Basil successfully. Mulch heavily to conserve soil moisture.
Valley County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.4
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
Basil Planting Timeline — Valley County, ID
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 23 | Apr 23 – May 7 |
| Transplant Outdoors | July 9 | Jul 9 – Jul 23 |
| Direct Sow | June 25 | Jun 25 – Jul 16 |
| Harvest | September 3 | Sep 3 – Nov 5 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors |
| June | Direct Sow |
| July | Transplant Outdoors Direct Sow |
| August | — |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
50–75 days
Soil pH
6 – 7
USDA Zone
Zone 4b
Growing Season
77 days
Growing Tips for Valley County
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Valley County, ID?
Valley County is in Zone 4b with an average last frost of June 18. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Valley County, ID?
Valley County, Idaho is in USDA Hardiness Zone 4b. The average last spring frost is June 18 and first fall frost is September 3.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Valley County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
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