When to Plant Horseradish in San Joaquin County, CA
Horseradish is a vigorous perennial grown for its pungent, spicy roots used as a condiment. Once established, it can be difficult to eradicate, so choose its location carefully.
San Joaquin County, California is in USDA Zone 9a. The average last spring frost is February 4 and the first fall frost is December 6, giving you a growing season of approximately 305 days.
At an elevation of 220 feet, San Joaquin County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Horseradish during the growing season. With low rainfall, drip irrigation is essential for growing Horseradish successfully. Mulch heavily to conserve soil moisture.
San Joaquin County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.8
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.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Horseradish Planting Timeline — San Joaquin County, CA
Horseradish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 18 | Feb 18 – Mar 4 |
| Harvest | June 24 | Jun 24 – Sep 2 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | — |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
120–180 days
Soil pH
6 – 7.5
USDA Zone
Zone 9a
Growing Season
305 days
Growing Tips for San Joaquin County
Plant root cuttings at a 45-degree angle in early spring. Harvest roots in late fall for strongest flavor. Contain the plant with barriers or grow in large containers.
Companion Planting
Good Companions
Level Up Your Garden
Horseradish in Other Locations
Frequently Asked Questions
When should I plant Horseradish in San Joaquin County, CA?
San Joaquin County is in Zone 9a with an average last frost of February 4. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Joaquin County, CA?
San Joaquin County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 4 and first fall frost is December 6.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help San Joaquin County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.
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