USDA Hardiness Zone 8b
Frost Dates for 93453 — Santa Margarita, California
Averages from Twitchell Dam, Ca US, the nearest reporting station, 26.8 miles away.
Plant tender crops after February 4, and expect the first autumn freeze around December 4. That leaves about 301 frost-free days.
- Last spring frost
- February 4
- First fall frost
- December 4
- Growing season
- 301 days
- Hardiness zone
- 8b
50% probability
50% probability
frost-free
15 to 20°F annual low
Planting calendar for 93453
| When | What to do |
|---|---|
| November 26 – December 10 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| December 10 – December 24 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| January 7 – January 21 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| February 4 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by September 11 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by November 20 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| December 4 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after February 4 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Santa Margarita, California are past their last freeze. Harvest before December 4, which leaves roughly 301 frost-free days.
ZIP 93453 sits in USDA hardiness zone 8b, meaning the average coldest night of the year falls between 15 to 20°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.