What Grows in San Carlos, Arizona

The last hard freeze (28°F) in San Carlos typically lands around Feb 8, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Mar 1.

The first hard freeze (28°F) in San Carlos typically arrives around Dec 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 18, so the watching starts about Nov 2 — about 297 days after the spring freeze cleared.

Measured between 28°F hard freezes, San Carlos sees about 297 frost-free days — roughly Feb 8 through Dec 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 1 to Nov 18, about 262 days.

The federal record around San Carlos is a meaningful one — 7 documented sites, mostly Mining entries (5), the nearest Superfund record about 1.6 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.

From about Nov 2 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Dec 2 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Dec 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.