What Growing Zones Are in California?
California is the third largest state and top agricultural producer in America, but it includes a huge diversity of landscapes. Former organic Farmer Logan Hailey explains the diversity of growing zones in California and what plants you can grow in the Golden State.
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From the subtropical warmth of L.A. and the southern coast to the frigid high elevations of the Sierra Nevada mountains, California is home to a huge diversity of landscapes.
The majority of the state stays comfortable for gardening almost year-round, with lows averaging 20°F (-6°C) and average highs around 70-80°F (21-27°C). This Mediterranean-like climate includes dry, hot summers and mild, wet winters, so it is no surprise that California is America’s top agricultural producer.
California is the third largest state in the U.S., with a massive range of climates and growing zones across over 150,000 square miles. The impact of coastal weather, inland valleys, and desert weather creates unique microclimates that can dramatically affect what plants you should grow in your California landscape.
For gardeners in the Golden State, it’s helpful to know exactly where your garden fits on the USDA growing zone chart so you can choose the right species for year-round cultivation. Let’s dig into the six growing zones (12 subzones) found in the state of California!
What Growing Zones Are in California? USDA Zones 5-11
California has a huge diversity of growing zones, ranging from frigid mountainous zone 5a to subtropical SoCal zones 11a. Most of the state has a mild Mediterranean-like climate, making it perfect for cultivating tree fruit, nuts, wine grapes, vegetables, herbs, and a huge range of livestock.
The coastal and southern areas range from zone 8 to 10, while the eastern and mountainous regions of the state are predominantly zones 6-7. The highest elevation regions dip into the subalpine zone 5 range.
For gardeners along the northern California coast, USDA zones 9a and 9b are the most common. Gardeners in San Francisco, Los Angeles, and San Diego can grow even warmer-climate crops in zones 9b through 11a. The Central Valley has a very temperate, mild climate, including zones 9a to 9b. The warmest regions of southern California are almost tropical zones 10b and 11a, with winter weather that rarely gets below freezing.
The coldest regions of California are in the Sierra Nevada mountains along the eastern side of the state, with Lassen County and parts of Tuolumne, Fresno, and Mono counties encompassing the coldest zone 5a areas, with annual extreme minimums as low as -20°F (-29°C).
Zone 5
The most frigid growing zones in California are found in the eastern part of the state at high elevations of the Sierra Nevadas. Most of us think of California as warm, sunny coastlines full of surfers and bikini-clad beachgoers, but the mountainous areas can dip into negative temperatures as cold as -20°F (-29°C) during extreme winters.
Gardeners living in the Sierras are surely already acquainted with the snowy winters and ski resorts, but that doesn’t mean they can’t grow food. Zone 5a and 5b still have a medium-length growing season, with estimated frost-free months from May to October.
Zone 6
The foothills of the Sierra Nevada mountain range are predominantly zones 6a and 6b, including Lake Tahoe and Bridgeport. These growing zones have extreme minimums of around -10 to -15°F (-23 to -26°C) but are still home to excellent gardening opportunities.
Zone 6 gardeners in California can reliably grow vegetables from late April to October. They can still grow a huge diversity of perennials, from delicious apples and pears to fragrant lilacs and cold-hardy hydrangeas.
Zone 7
Several thousand square miles of land around the Cascade and Sierra Nevada mountain ranges encompass zone 7. This includes Lassen, Shasta, and Plumas counties in NorCal, down to the eastern parts of Placer, Sonora, and Fresno counties, as well as large parts of the Yosemite Valley.
Zones 7a and 7b have annual minimum temperatures of 0 to 5°F (-18 to -15°C) and 5 to 10°F (-15 to -12°C), respectively. These areas still have a medium-length growing season from mid-April to November, with ample frost-free days for growing warm-weather annuals. There can be a huge variation in weather across different zone 7 elevations and microclimates. Be sure to check a frost date calculator for the most accurate estimations of your growing season.
Zone 8
Much of Northern California and the foothills of the Sierras reside in growing zone 8. Zones 8a and 8b cover huge swaths of land from the Mojave and Sonoran deserts to the Central Valley and all along the inland coastal counties. These areas experience some frosts, with annual minimum extremes from 10 to 20°F (-12 to -6°C), but they don’t often dip into negative temperatures.
This temperate growing region is ideal for vegetable production and provides ample time for cool-weather crops like brassicas (kale, cabbage, broccoli, etc.) that might have trouble growing in zone 9 summers. Fruit options for zone 8 include apples, figs, persimmons, blueberries, grapes, and kiwi vines. Sage, lavender, rosemary, and oregano also thrive in these areas.
Zone 9
The majority of coastal and central California falls into zones 9a or 9b, which offer a nearly endless array of potential crops you can grow in your garden. As you move from eastern California to the West Coast, the climate gets warmer and milder. These areas are more amenable to the more famous California crops like grapes, olives, citrus, and almonds.
Zone 9 marks the transition into a truly Mediterranean-like climate. The infamous Central Valley is predominately zone 9b. With warm, dry summers and mild, moist winters, it is a hub for agricultural activity. The frost-free growing season is long, from approximately March to December. This allows ample time for gardeners to grow almost anything their heart desires!
If you love fruit trees, zone 9 is the golden zone of California! This growing zone is perfect for cultivating warm-climate fruits like oranges, lemons, olives, figs, pears, peaches, and even tropical trees like avocado and papaya. Vegetable gardeners in zone 9 are equally blessed with an abundance of opportunities to grow warm-weather crops like tomatoes, peppers, melons, and cucumbers almost year-round!
Zone 10a
As you reach the urban areas of San Francisco and south to Los Angeles, zone 10a is officially subtropical. These areas experience almost year-round summer and very rarely dip below freezing. Most of the Bay Area and Los Angeles reside in zone 10. These are some of the easiest places to garden; you can grow year-round without worrying about extreme winters or frigid springs.
Zone 10 is perfect for several seasonal successions of nearly every type of vegetable, plus endless opportunities for fruit trees, perennial Mediterranean herbs like lavender and rosemary, olive trees, wine or table grape vines. It’s also great for vibrant, sun-loving zone 10 flowers like ginger lilies and magnolias, plus diverse outdoor succulents like agave and cacti.
This is truly a gardener’s paradise because plants can flower and fruit freely without the risk of heavy frost. You can find lemon trees growing in abandoned lots and passionfruit vines growing wild along fence lines. Zone 10a can still occasionally dip below 32°F (0°C) and experience light frost, but it never experiences harsh winters.
Zones 10b and 11a
The warmest growing areas of Southern California include Los Angeles, San Diego, Palm Springs, and the Mojave desert. Some parts of the Bay Area and scattered areas along the coast also count as growing zone 10b and 11a. These areas never experience frost and consistently stay above 35-40°F (2-4°C). They are perfect for cultivating tropical and desert plants outdoors.
You can grow tomatoes, peppers, and basil as outdoor perennials in these zones. Tropical fruit trees like papaya, avocado, lychee, fig, mangoes, and dragon fruit are a must! Prickly pear, agave, and other desert succulents thrive in xeriscape gardens in the drought-prone areas of SoCal. Mulberries, magnolias, and camphor are excellent shade trees for zone 10b and 11a.
Final Thoughts
Overall, California is a diverse state that offers virtually endless opportunities for gardeners. Most of Western California is Growing Zone 8-10, While Eastern and Mountainous Parts Cover Zones 5-7. Southern California and the inland deserts are mostly subtropical and rarely experience frost.
The coastal regions and Central Valley regions are predominantly zones 8-11. They have a Mediterranean-like climate with warm, dry summers and mild winters. Eastern and Northern California can get much colder at high elevations of the Sierra Nevada and Cascade mountains, dipping into zones 5 through 7.