Zone 10 Planting Calendar: What to Plant Each Month

Soil beats calendar. Extension guidance for the hardiest crops is “as soon as the soil can be worked” or “as soon as the soil thaws” — not a fixed date. If you cannot crumble a handful of soil in your fist, wait, whatever the table says. Warm-season crops have a matching rule: beans want 60°F soil, cucumbers and squash 70°F.

Heat is your limiting factor, not frost. With 339 frost-free days, the hard part of the zone 10 year is midsummer. Lettuce and spinach bolt bitter above 80°F, so move them to autumn and late winter rather than fighting July. The fall sowing dates above are the important ones here.

About the bolting warnings. Cool-season crops run to seed and turn bitter in summer heat. The “may bolt in heat” flag above is a rough calendar rule — mid-June to the start of September, the same window across the whole country — because a hardiness zone carries no summer-temperature information at all. In zone 10 treat it as understated; your hot spell starts earlier and runs later, and heat-tolerant varieties plus afternoon shade matter.

Where these dates come from. A USDA hardiness zone describes average annual extreme minimum WINTER temperature — it is a winter-survival rating for perennials, not a frost-date band. The frost dates below are widely-used approximations for each zone, not official USDA figures, and a single zone spans hundreds of miles. Treat them as a default guess and replace them with your own local averages wherever you have them.

You can enter your own frost dates in the interactive calendar and every window on it recalculates from your numbers. Look up your local averages on the NOAA last-spring-freeze map. Note that an “average” frost date is the point where the chance of freezing drops below 50 percent, so for tender crops it is worth waiting a week or two past it.