Frost Dates & Planting Calendar for Rio Del Mar, CA

The average first fall frost in Rio Del Mar, CA is December 13, and the average last spring frost is January 29, giving a growing season of about 323 days.

Plan your garden around Rio Del Mar, CA's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.

Last Spring Frost

January 29

Safe Feb 28 Typical Jan 29 Risky Dec 25

First Fall Frost

December 13

Safe Nov 23 Typical Dec 13 Risky Jan 22

Growing Season

323 days

Typical last frost to typical first frost.

USDA Hardiness Zone

Zone 9b

Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.

Data: NOAA station SANTA CRUZ, CA US, 9.1 km away.

— days until the typical last spring frost

How Rio Del Mar Compares

Rio Del Mar's typical last spring frost (Jan 29) comes later than in 57% of the 427 California cities we track.
Its 323-day growing season is 14 days shorter than the California median of 337 days.
Rio Del Mar shares its NOAA weather station with Capitola (5 km away), so their typical frost dates are the same.
September is the warmest month (average high 77°F) and December the coldest (average low 41°F).

Monthly Temperatures

Avg. high Avg. temp Avg. low

Planting Calendar

Vegetables
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Tomato	Dec 4 – Dec 18	—	Feb 5 – Feb 12	—	60–85 days	Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed.
Pepper	Nov 20 – Dec 4	—	Feb 5 – Feb 19	—	60–90 days	Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost.
Eggplant	Nov 20 – Dec 4	—	Feb 12 – Feb 19	—	65–85 days	Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant.
Cucumber	Jan 1 – Jan 8	Feb 5 – Feb 12	Feb 5 – Feb 12	—	50–65 days	Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm.
Zucchini	Jan 8 – Jan 15	Feb 5 – Feb 19	Feb 5 – Feb 12	—	45–55 days	Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start.
Winter Squash	Jan 1 – Jan 8	Feb 5 – Feb 19	Feb 5 – Feb 12	—	80–110 days	Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates.
Pumpkin	—	Feb 5 – Feb 19	—	—	90–120 days	Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it.
Watermelon	Jan 1 – Jan 8	—	Feb 12 – Feb 19	—	70–90 days	Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost.
Cantaloupe	Jan 1 – Jan 8	—	Feb 12 – Feb 19	—	70–90 days	Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting.
Corn	—	Jan 29 – Feb 12	—	—	60–100 days	Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks.
Green Bean	—	Jan 29 – Feb 12	—	—	50–65 days	Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush.
Pea	—	Dec 18 – Jan 1	—	—	55–70 days	Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Lettuce	—	Jan 1 – Jan 15	—	Oct 18 – Nov 1	45–60 days	Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts.
Spinach	—	Dec 18 – Jan 1	—	Oct 18 – Nov 1	40–50 days	Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Kale	—	Jan 1 – Jan 15	—	Oct 4 – Oct 18	50–65 days	Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants.
Arugula	—	Jan 1 – Jan 15	—	Nov 1 – Nov 8	30–40 days	Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks.
Swiss Chard	—	Jan 8 – Jan 22	—	—	50–60 days	Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too.
Broccoli	Dec 11 – Dec 25	—	Jan 8 – Jan 15	Oct 11 – Oct 18	55–80 days	Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost).
Cauliflower	Dec 11 – Dec 25	—	Jan 15 – Jan 22	Oct 4 – Oct 11	55–85 days	Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost.
Cabbage	Dec 11 – Dec 25	—	Jan 1 – Jan 15	Oct 4 – Oct 18	60–100 days	Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost.
Brussels Sprouts	Dec 11 – Dec 25	—	Jan 8 – Jan 22	—	90–110 days	Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost.
Carrot	—	Jan 1 – Jan 15	—	Sep 20 – Oct 4	60–80 days	Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked.
Beet	—	Jan 1 – Jan 15	—	Oct 4 – Oct 18	50–65 days	Direct sow 2-4 weeks before last frost; tolerates light frost.
Radish	—	Dec 25 – Jan 8	—	Nov 1 – Nov 15	22–30 days	Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked.
Turnip	—	Jan 1 – Jan 15	—	Oct 4 – Oct 18	40–60 days	Cold-hardy; direct sow 2-4 weeks before last frost.
Onion	Nov 20 – Dec 4	—	Jan 1 – Jan 15	—	90–120 days	Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings.
Garlic	—	—	—	Nov 15 – Nov 29	240–270 days	Fall-planted crop only; not planted in spring in most climates.
Potato	—	Jan 1 – Jan 15	—	—	70–120 days	Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated.
Sweet Potato	—	—	Feb 12 – Feb 26	—	90–120 days	Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive.
Asparagus	—	—	Jan 1 – Jan 15	—	730–1095 days	Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production.

Herbs
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Basil	Dec 18 – Dec 25	—	Feb 5 – Feb 12	—	50–70 days	Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm.
Cilantro	—	Jan 8 – Jan 22	—	Oct 18 – Nov 1	45–70 days	Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring.
Parsley	Dec 4 – Dec 18	—	Jan 15 – Jan 22	—	70–90 days	Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant).
Dill	—	Jan 8 – Jan 22	—	—	40–60 days	Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer.
Oregano	Dec 4 – Dec 18	—	Jan 29 – Feb 5	—	80–90 days	Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date.
Thyme	Dec 4 – Dec 18	—	Jan 29 – Feb 5	—	85–95 days	Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost.

Flowers
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Sunflower	—	Feb 5 – Feb 19	—	—	70–100 days	Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting.
Zinnia	Jan 1 – Jan 8	Feb 5 – Feb 19	Feb 5 – Feb 12	—	60–70 days	Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms.
Marigold	Dec 18 – Jan 1	—	Feb 5 – Feb 12	—	45–60 days	Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed.
Cosmos	Jan 1 – Jan 8	Feb 5 – Feb 19	Feb 5 – Feb 12	—	60–90 days	Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early.
Nasturtium	—	Feb 5 – Feb 19	—	—	50–65 days	Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed.
Dahlia	—	—	Feb 5 – Feb 19	—	90–120 days	Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive.

Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.

Frequently Asked Questions

When is the last frost in Rio Del Mar, CA?

Based on 1991–2020 NOAA climate normals for the SANTA CRUZ, CA US station, the last spring frost in Rio Del Mar typically falls around January 29. A cautious gardener might wait until February 28 (only a 10% chance of a later frost), while December 25 marks an earlier, higher-risk planting date.

When is the first frost in Rio Del Mar, CA in fall?

The first fall frost in Rio Del Mar typically arrives around December 13. To stay safe, assume frost could start as early as November 23; in milder years it can hold off until January 22.

How long is the growing season in Rio Del Mar, CA?

Rio Del Mar's average frost-free growing season is about 323 days, running from the typical last spring frost (January 29) to the typical first fall frost (December 13).

What USDA hardiness zone is Rio Del Mar, CA in?

Rio Del Mar, CA is in USDA plant hardiness zone 9b, per the USDA's 2023 Plant Hardiness Zone Map. Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.