When to Plant Kale in Riverside County, CA
Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.
Riverside County, California is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is December 4, giving you a growing season of approximately 283 days.
At an elevation of 1,206 feet, Riverside County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Kale may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Kale successfully. Mulch heavily to conserve soil moisture.
Riverside County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 10/10 — consider drought-tolerant varieties and mulching
Kale Planting Timeline — Riverside County, CA
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 27 | Jan 27 – Feb 10 |
| Transplant Outdoors | February 24 | Feb 24 – Mar 10 |
| Direct Sow | February 3 | Feb 3 – Feb 24 |
| Fall Sowing | October 9 | Oct 9 – Oct 23 |
| Harvest | April 21 | Apr 21 – Jun 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
50–70 days
Soil pH
6 – 7.5
USDA Zone
Zone 9b
Growing Season
283 days
Growing Tips for Riverside County
Direct sow or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) — they all cross.
Kale in Other Locations
Frequently Asked Questions
When should I plant Kale in Riverside County, CA?
Riverside County is in Zone 9b with an average last frost of February 24. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Riverside County, CA?
Riverside County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is December 4.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Riverside County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.
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