When to Plant Eggplant in Napa County, CA
Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.
Napa County, California is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.
At an elevation of 449 feet, Napa County receives approximately 35 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Eggplant during the growing season.
Napa County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.5
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 6/10 — consider drought-tolerant varieties and mulching
Eggplant Planting Timeline — Napa County, CA
Eggplant Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 15 | Jan 15 – Jan 29 |
| Transplant Outdoors | March 5 | Mar 5 – Mar 19 |
| Direct Sow | February 26 | Feb 26 – Mar 19 |
| Harvest | May 14 | May 14 – Jul 16 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
65–85 days
Soil pH
5.5 – 7
USDA Zone
Zone 9a
Growing Season
273 days
Growing Tips for Napa County
Start seeds indoors 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Eggplant in Other Locations
Frequently Asked Questions
When should I plant Eggplant in Napa County, CA?
Napa County is in Zone 9a with an average last frost of February 26. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.
What planting zone is Napa County, CA?
Napa County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Napa County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.
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