California planting calendar

When to plant asparagus in California — sow, transplant & harvest dates

California is mostly USDA zone 9b (range 5a-11a). Dates below are derived from asparagus's frost tolerance and California's frost window — not generic national averages.

Asparagus planting timetable for California

Stage	When in California	Anchor
Direct-sow / set out (spring crop)	late January (January 25)	-21 days after the last frost (mid-February (coast) to late April (interior))
Spring-crop harvest	late January onward, before peak summer heat	730-day crop — finishes before mid-summer
Plant the fall crop	early November (November 1) — once the worst heat breaks	~744 days before the first fall frost (mid-November (coast) to mid-October (interior))
Fall-crop harvest	early November into early winter	730-day crop — often the more productive of the two

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why California's climate shifts the asparagus dates

California's long hot summer shuts down fruit set, so locals run two short crops — a spring planting and a fall planting — around a deliberate mid-summer pause, instead of one long northern-style season. California packs more climate diversity than almost any state — alpine mountains, Mediterranean coast, Central Valley farmland, and desert. Coastal and valley areas grow year-round.

Asparagus is almost always established from year-old crowns rather than seed; plant them in a prepared trench 20-30 cm deep as soon as the soil can be worked in early spring, 2-3 weeks before the last frost. Do not harvest at all in year one, harvest sparingly for 2-3 weeks in year two, and from year three onward you can take a full 6-8 week spring harvest. Crowns are reliably cold-hardy to zone 3 but require winter dormancy — they are poorly suited to zones 10-11 where winters are too warm to meet the chilling requirement.

Frost-risk note

A light frost in the high Sierra Nevada (zone 5a-6a) can clip an early spring planting; the bigger risk is mid-summer heat sterilising flowers.

Regional variation within California

the southern coast and Imperial Valley (zone 11a) can start the spring crop weeks earlier and may garden almost year-round; the high Sierra Nevada (zone 5a-6a) runs a shorter, more northern-style single season.

Los Angeles — USDA zone 10b
San Francisco — USDA zone 10b
Sacramento — USDA zone 9b
San Diego — USDA zone 10b
Fresno — USDA zone 9b

What else to plant in California around then

Pair the spring slot with other heat-lovers (peppers, squash, beans); use the cool October–February window for greens and brassicas.

Quick-grow guide

Sun: Full sun — 6-8 hours direct.
Soil temperature for germination: Soil 10-18 °C (50-65 °F) at crown planting.
Spacing: 12-18 inches (30-45 cm) between plants.
Days to harvest: ~730 days from planting out.

Frequently asked questions

When is the best time to plant asparagus in California?

In California (mostly USDA zone 9b), set the spring crop out late January, harvest before peak summer heat, then plant a second crop early November for an autumn harvest. Avoid mid-summer. Asparagus are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

What USDA zone is California?

Most of California sits in USDA hardiness zone 9b, with the state spanning roughly 5a-11a from the high Sierra Nevada (zone 5a-6a) to the southern coast and Imperial Valley (zone 11a). The last spring frost averages mid-February (coast) to late April (interior) and the first fall frost mid-November (coast) to mid-October (interior).

Can you grow asparagus in California?

Yes. California's dominant zone 9b supports asparagus — the key is timing. Asparagus are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across California?

What else can I plant in California around the same time?

Pair the spring slot with other heat-lovers (peppers, squash, beans); use the cool October–February window for greens and brassicas.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.