Riverside, CA · zone 9b · ~350 frost-free days
When to plant a garden in Riverside.
In Riverside, the typical last spring frost lands around Jan 10 and the first fall frost around Dec 26, giving you about 350 frost-free days. Cool-season crops go out before the last frost; warm-season crops wait until after it.
The 2026 windows
Sow dates for Riverside, keyed to your frost.
| Crop | Start indoors | Spring sow / set out | Fall sow |
|---|---|---|---|
| Tomato, slicing | Dec 6 to Feb 5 | Jan 17 to Mar 19 | — |
| Lettuce, leaf | — | Jan 1 to Jan 17 | Oct 12 to Dec 11 |
| Carrot | — | Jan 1 to Jan 5 | Sep 30 to Oct 26 |
| Bush Bean | — | Jan 10 to Mar 2 | Sep 11 to Oct 14 |
| Cucumber, slicing | — | Jan 17 to Apr 18 | Aug 25 to Sep 25 |
| Pepper, bell | Dec 15 to Feb 5 | Jan 26 to Mar 19 | — |
| Kale | Nov 20 to Nov 20 | Jan 1 to Jan 1 | Sep 25 to Nov 10 |
| Spinach | — | Jan 1 to Jan 1 | Oct 12 to Nov 30 |
Riverside sits in Zone 9b, but two gardens in the same city can be a week or two apart. The planner works from your ZIP code's frost dates, not the zone, so the dates land right for your block, not the metro average.
Build your Riverside garden plan.
Tell the free planner what you want to eat and who you're feeding. It returns plant counts, spacing, and frost-safe sow dates for ZIP 92501 in about 60 seconds.