Los Angeles, CA

Los Angeles sits at the boundary between subtropical and Mediterranean climates within zone 10b. Winter lows rarely drop below 35°F, and the last measurable spring frost occurs around December 31, while the first fall frost arrives around December 28. In practical terms, this means a year-round growing season of 365 days with minimal frost risk. The dominant constraint is not cold but heat and water. Summer temperatures regularly exceed 85°F inland, and humidity stays low. This climate suits heat-loving perennials and annuals exceptionally well: figs thrive here as woody shrubs, tomatoes and peppers produce for months longer than in colder zones, and herbs like rosemary grow vigorously year-round. Cool-season crops (lettuce, kale, broccoli) work, but their window is compressed. Rather than the traditional spring-summer schedule of other zones, Los Angeles gardening splits into two main seasons: a mild, moist period from November through April when cool-season crops shine and warm-season crops are slow to establish, and a hot, dry period from May through October when heat-lovers dominate and water becomes the binding resource.

Rather than frost, which limits gardeners in colder zones, Los Angeles gardeners face three practical challenges that commonly cause failures. First, summer heat (May through October) causes spring-planted tomatoes and peppers to wilt, develop sunscald, or drop flowers without supplemental afternoon shade and consistent irrigation. Early-summer heat waves in May or June stress young transplants before they're established. Second, alkaline soil is common throughout coastal and inland Los Angeles, pushing pH above 7.5 and locking up micronutrients like iron and manganese. Peppers and figs tolerate alkalinity, but tomatoes and leafy greens show chlorosis without soil amendment. Third, the region's water availability is unpredictable and increasingly restricted. Even though winter rains are possible, relying on rainfall alone is unrealistic in modern Los Angeles, and many home gardeners face water-use restrictions that require drip irrigation and heavy mulching to stay within limits while maintaining production.

Start cool-season crops (lettuce, kale, brassicas) in August or September for harvest through early spring, rather than in spring as gardeners in colder zones do. Fall-planted crops germinate reliably in cooling soil (75°F by late August) and mature before late May when summer heat arrives. Second, use shade cloth from April through September to extend the harvest window for spring-planted tomatoes and peppers. Thirty to fifty percent shade cloth deployed by mid-May prevents sunscald and reduces water needs by 20 to 30 percent without sacrificing yield. Third, prioritize drip irrigation and mulch aggressively. Shallow-rooted crops like basil and peppers need consistent soil moisture through the hot months; 3 to 4 inches of wood chip mulch reduces irrigation frequency and moderates soil temperature. Hand-watering or sprinklers in Los Angeles are increasingly impractical given both water restrictions and the labor involved in watering daily during heat waves.