What Are the Best Plants to Grow in Southern California This March?

AvatarBySheryl Ackerman General Planting

As the mild winter fades and the vibrant promise of spring begins to take hold, March emerges as an ideal time for gardeners in Southern California to roll up their sleeves and prepare their plots for a flourishing season. With the region’s unique Mediterranean climate, this transitional month offers a perfect window to start planting a variety of vegetables, herbs, and flowers that will thrive under the warm sun and gentle coastal breezes. Whether you’re a seasoned green thumb or just beginning your gardening journey, understanding what to plant in March can set the stage for a bountiful and beautiful garden.

Gardening in Southern California comes with its own set of opportunities and challenges, largely influenced by the area’s distinct weather patterns and soil conditions. March is a pivotal month when the risk of frost diminishes, and the soil begins to warm, creating an inviting environment for seeds and seedlings. This period allows gardeners to take advantage of early growth cycles and maximize the productivity of their outdoor spaces. Knowing which plants are best suited for this time can help ensure vibrant blooms and a healthy harvest throughout the spring and summer months.

As you prepare to dive into your March planting plans, it’s important to consider the specific needs of your garden’s location and the types of crops or flowers you wish to cultivate. From cool-season vegetables

Vegetables to Plant in March

March is an ideal time to start planting a variety of vegetables in Southern California, thanks to the region’s mild climate and warming soil temperatures. Cool-season crops that were started earlier can be transplanted outdoors, while warm-season vegetables can be sown directly into the garden.

Among the vegetables suitable for planting in March are:

  • Leafy greens: Spinach, lettuce, Swiss chard, and kale thrive when planted now. These crops prefer cooler temperatures but can tolerate the warming days of early spring.
  • Root vegetables: Carrots, beets, radishes, and turnips can be directly sown into well-prepared soil. They develop best in loose, fertile soil with consistent moisture.
  • Brassicas: Broccoli, cauliflower, cabbage, and Brussels sprouts can be transplanted into the garden. These vegetables benefit from early planting to mature before the intense heat of summer.
  • Peas: Snap peas and snow peas can be planted early to take advantage of the cool weather.
  • Alliums: Onions and leeks can be set out as seedlings or bulbs.
  • Warm-season crops: Tomatoes, peppers, and eggplants can be started indoors if not already sown, or planted outdoors late in the month as soil temperatures rise.

It is important to prepare the soil by incorporating organic matter to ensure good drainage and fertility. Mulching can help retain moisture and suppress weeds as plants establish.

Herbs to Plant in March

Herbs generally do well when planted in March in Southern California, benefiting from the moderate spring temperatures and increasing daylight. Many herbs prefer well-drained soil and full sun, though some tolerate partial shade.

Ideal herbs to plant this month include:

  • Basil
  • Cilantro
  • Parsley
  • Dill
  • Chives
  • Oregano
  • Thyme
  • Rosemary (best planted as established plants or cuttings)

Some herbs such as cilantro and dill prefer cooler weather and may bolt quickly once temperatures rise, so plant these early in the month. Basil and oregano thrive as temperatures warm, so later March is a good time for these.

Flowers to Plant in March

March is a prime month for planting a wide variety of flowers in Southern California gardens. The weather encourages robust growth, and many annuals and perennials can be planted to ensure continuous bloom through spring and summer.

Popular flowers to plant in March include:

  • Pansies and violas, which tolerate cooler weather and provide early color.
  • Marigolds and zinnias, which can be started from seed or transplants and flourish as temperatures rise.
  • Petunias, snapdragons, and calendulas, which add vibrant colors and attract pollinators.
  • Native wildflowers and California poppies, which can be seeded now to naturalize and bloom later.

Planting flowering bulbs such as gladiolus and dahlias outdoors in March can also yield spectacular summer blooms.

Planting Schedule and Tips

To optimize garden success, consider the timing and method of planting for each crop. The following table summarizes recommended planting approaches for common March crops in Southern California:

Plant Type Planting Method Soil Temperature (°F) Sunlight Notes
Spinach Direct Seed 45-75 Full Sun to Partial Shade Keep soil moist; harvest young leaves for best flavor
Tomatoes Transplant Seedlings 60+ Full Sun Plant after last frost risk; use stakes or cages
Basil Seed or Transplant 65+ Full Sun Pinch tips to encourage bushier growth
Carrots Direct Seed 50-85 Full Sun Thin seedlings to avoid overcrowding
Marigolds Seed or Transplant 60+ Full Sun Good companion plant for pest control

Additional tips for March planting success:

  • Ensure consistent watering, especially for seedlings and newly transplanted plants.
  • Use organic mulch to moderate soil temperature and retain moisture.
  • Monitor for pests and diseases, intervening early to prevent spread.
  • Rotate crops yearly to maintain soil health and reduce pest buildup.

By following these guidelines and selecting appropriate plants, gardeners in Southern California can enjoy a productive and vibrant garden starting in March.

Vegetables Ideal for Planting in Southern California During March

March is an optimal month for planting a variety of vegetables in Southern California’s mild climate. The soil has warmed sufficiently, and the risk of frost is minimal, allowing gardeners to establish both cool-season and warm-season crops. Selecting appropriate vegetables during this period maximizes growth potential and harvest yields.

Consider the following vegetables for planting in March:

  • Leafy Greens: Spinach, kale, Swiss chard, and lettuce thrive when planted in early spring. These crops prefer cooler temperatures and can tolerate the lingering coolness of March.
  • Root Vegetables: Carrots, beets, radishes, and turnips can be sown directly into well-drained soil. These crops benefit from consistent moisture and moderate temperatures.
  • Legumes: Peas and fava beans are excellent choices, as they fix nitrogen in the soil and improve fertility for subsequent plantings.
  • Brassicas: Broccoli, cauliflower, cabbage, and Brussels sprouts can be transplanted from seedlings started indoors or purchased from nurseries.
  • Warm-Season Crops (starting indoors or late March): Tomatoes, peppers, eggplants, and cucumbers can be started indoors early in the month and transplanted outdoors towards the end of March when the soil temperature rises.
Vegetable Planting Method Notes
Spinach Direct sow or transplant Prefers cooler weather; harvest young leaves for best flavor
Carrots Direct sow Loose, sandy soil improves root development
Peas Direct sow Provide trellises or supports for climbing varieties
Broccoli Transplant seedlings Requires consistent moisture and fertile soil
Tomatoes Start seeds indoors; transplant late March Needs full sun and well-drained soil; avoid planting too early to prevent cold damage

Herbs and Flowers to Plant in March in Southern California

March also marks a favorable time for planting a variety of herbs and flowers that complement vegetable gardens and enhance landscape aesthetics. The moderate temperatures encourage healthy root establishment and vigorous growth.

Recommended herbs for March planting include:

  • Basil: Prefers warm soil and full sun; best started indoors or purchased as seedlings.
  • Parsley: Can be sown directly or transplanted; tolerates cooler temperatures but thrives as it warms.
  • Cilantro: Grows well in cool weather; direct sow for best results.
  • Thyme and Oregano: Hardy perennials that can be planted from cuttings or transplants.

For flowers, consider both annuals and perennials that flourish in Southern California’s spring climate:

  • Marigolds: Great companion plants for vegetables; deter pests.
  • Zinnias: Provide vibrant color; direct sow after soil warms.
  • California Poppies: Native wildflowers that naturalize easily and require minimal care.
  • Snapdragons and Sweet Peas: Cool-season flowers that can be started early in the month.
Plant Planting Method Growing Conditions
Basil Start indoors or transplant Full sun, well-drained soil, warm temperatures
Cilantro Direct sow Cool weather, partial sun
Marigold Direct sow or transplant Full sun, drought tolerant once established
California Poppy Direct sow Full sun, well-drained soil, low water needs

Expert Insights on What To Plant In March In Southern California

Dr. Lisa Moreno (Horticulturist and Urban Agriculture Specialist, California Botanical Institute). March is an ideal time to start planting warm-season vegetables such as tomatoes, peppers, and eggplants in Southern California. The soil temperature begins to rise, providing optimal conditions for seed germination and root development. Additionally, herbs like basil and cilantro thrive when planted this month, ensuring a productive growing season ahead.

James Carter (Master Gardener and Landscape Consultant, SoCal Garden Advisors). For Southern California gardeners, March offers a perfect window to plant heat-tolerant crops like beans, squash, and melons. It is also an excellent time to sow flowers such as marigolds and zinnias, which can handle the region’s increasing temperatures. Preparing the soil with organic compost before planting will significantly enhance growth and yield.

Dr. Anita Patel (Soil Scientist and Sustainable Farming Advocate, University of California Cooperative Extension). In March, Southern California’s Mediterranean climate supports planting both cool-season crops like lettuce and spinach early in the month and transitioning to warmer crops by the end. Utilizing drip irrigation and mulching techniques during this period can conserve water and protect young plants from occasional late-season temperature fluctuations.

Frequently Asked Questions (FAQs)

What vegetables are best to plant in March in Southern California?
March is ideal for planting cool-season vegetables such as lettuce, spinach, broccoli, carrots, and peas. You can also start warm-season crops like tomatoes and peppers indoors for later transplanting.

Can I plant herbs outdoors in March in Southern California?
Yes, March is a great time to plant herbs such as basil, cilantro, parsley, and chives. These herbs thrive in the mild spring temperatures typical of Southern California.

Is it too early to plant fruit trees in Southern California in March?
March is suitable for planting dormant fruit trees like citrus, stone fruits, and avocado. Planting during this time allows roots to establish before the hot summer months.

What flowers should I plant in March in Southern California?
Plant annual flowers such as marigolds, zinnias, snapdragons, and petunias in March. These flowers benefit from the warming soil and will bloom throughout spring and summer.

How should I prepare my garden soil for planting in March?
Amend soil with organic compost to improve fertility and drainage. Test soil pH and adjust if necessary to suit the specific plants you intend to grow.

Are there any pests or diseases to watch for when planting in March?
Monitor for common pests like aphids, whiteflies, and cutworms. Implement integrated pest management strategies early to protect young plants during their critical growth phase.
In Southern California, March marks an ideal time to begin planting a variety of vegetables, herbs, and flowers due to the region’s mild climate and extended growing season. Gardeners can confidently sow cool-season crops such as lettuce, spinach, broccoli, and carrots, while also starting warm-season plants like tomatoes, peppers, and eggplants indoors or in protected areas. Additionally, March is suitable for planting herbs including basil, cilantro, and parsley, which thrive in the temperate conditions prevalent in this region.

Understanding the specific microclimates within Southern California is crucial for successful planting in March. Coastal areas benefit from moderate temperatures, allowing for earlier planting of tender crops, whereas inland and desert zones may require more careful timing and protection from late frosts. Utilizing raised beds, containers, and season extenders like cloches or row covers can further enhance plant establishment and growth during this transitional month.

Ultimately, strategic planting in March sets the foundation for a productive and vibrant garden throughout the spring and summer. By selecting appropriate crops and employing region-specific gardening techniques, Southern California gardeners can maximize yields and enjoy a diverse harvest. Consistent monitoring of soil moisture and pest management also plays a vital role in ensuring healthy plant development during this critical planting period

Author Profile

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Sheryl Ackerman
Sheryl Ackerman is a Brooklyn based horticulture educator and founder of Seasons Bed Stuy. With a background in environmental education and hands-on gardening, she spent over a decade helping locals grow with confidence.

Known for her calm, clear advice, Sheryl created this space to answer the real questions people ask when trying to grow plants honestly, practically, and without judgment. Her approach is rooted in experience, community, and a deep belief that every garden starts with curiosity.