What Should You Plant in California This September?

AvatarBySheryl Ackerman General Planting

As the warm days of summer begin to wane and the crispness of autumn approaches, September presents a unique and exciting opportunity for gardeners in California. Whether you have a sprawling backyard or a modest balcony garden, this transitional month offers ideal conditions to sow seeds and nurture plants that will thrive in the cooler months ahead. Understanding what to plant in September can set the stage for a vibrant, productive garden that continues to flourish well into fall and winter.

California’s diverse climate zones—from coastal regions to inland valleys—mean that planting choices in September can vary widely, but the underlying principle remains the same: taking advantage of the milder temperatures and reduced summer heat. This period is perfect for introducing a variety of vegetables, herbs, and flowers that benefit from the gentle shift in weather. Gardeners who know how to align their planting schedule with the season’s rhythm can enjoy bountiful harvests and colorful blooms when many others are winding down.

In the following sections, we’ll explore the best plants to start this September in California, along with tips on soil preparation, watering, and care to ensure your garden’s success. Whether you’re a seasoned green thumb or just beginning your gardening journey, this guide will help you make the most of this pivotal month and cultivate a thriving garden through the

Vegetables Suitable for Planting in September

September is an ideal time to sow a variety of cool-season vegetables in California, as the temperatures begin to moderate and the risk of summer heat diminishes. This season favors crops that thrive in cooler soil and air temperatures, allowing them to mature during the mild fall and early winter months.

Key vegetables to plant include:

  • Leafy Greens: Spinach, kale, lettuce, Swiss chard, and arugula flourish in the cooler conditions and can be harvested well into the fall.
  • Root Vegetables: Carrots, beets, radishes, and turnips develop best when planted in early fall, as they benefit from consistent moisture and cooler soil.
  • Brassicas: Broccoli, cauliflower, cabbage, and Brussels sprouts are well-suited for September planting in California, especially in regions with mild winters.
  • Alliums: Onions and garlic can be planted in the fall for a spring harvest, especially in coastal and southern California zones.

Planting these vegetables now helps take advantage of the extended growing season and allows for a continuous harvest through the cooler months.

Herbs to Plant in September

Herbs can be a valuable addition to the September garden, as many varieties prefer the cooler temperatures that fall offers. Planting herbs in September encourages robust root development before the colder weather sets in.

Recommended herbs include:

  • Cilantro: Prefers cooler weather and tends to bolt quickly in summer heat, making fall ideal.
  • Parsley: Can be sown directly in the garden and tolerates light frosts.
  • Chives: Hardy perennials that establish well in fall.
  • Thyme and Oregano: These Mediterranean herbs thrive with fall planting, especially if transplanted from seedlings.

These herbs not only provide fresh flavors but also support beneficial insect populations in the garden.

Flower Bulbs and Perennials for Fall Planting

September is a prime time for planting many flower bulbs and perennials in California, as the soil remains warm enough to encourage root growth while the cooler air temperatures reduce stress on new plants.

Consider planting:

  • Spring-flowering bulbs: Tulips, daffodils, hyacinths, and crocuses should be planted in September to ensure vibrant blooms in spring.
  • Fall-blooming perennials: Chrysanthemums and asters can be planted now to add late-season color.
  • Native wildflowers: Planting native species in fall helps establish them before the dry summer season.

Planting flower bulbs and perennials during this period allows for successful overwintering and spectacular displays in the following seasons.

Plant Type Examples Planting Tips Harvest/ Bloom Time
Leafy Greens Spinach, Kale, Lettuce Sow seeds directly; ensure consistent moisture 6-8 weeks after planting
Root Vegetables Carrots, Beets, Radishes Loose, well-drained soil; thin seedlings 8-12 weeks after planting
Brassicas Broccoli, Cauliflower, Cabbage Transplant seedlings; protect from pests 10-14 weeks after transplanting
Herbs Cilantro, Parsley, Chives Plant seedlings or sow seeds; partial sun 4-8 weeks for harvest
Flower Bulbs Tulips, Daffodils, Hyacinths Plant bulbs 4-6 inches deep; well-drained soil Spring bloom

Soil Preparation and Care for September Planting

Proper soil preparation is critical to successful planting in September. With the transition from summer to fall, soil conditions improve but still require attention to maximize plant health.

  • Soil Testing: Conduct a soil test to determine pH and nutrient levels. Most vegetables prefer a slightly acidic to neutral pH (6.0 to 7.0).
  • Amendments: Incorporate organic matter such as compost or aged manure to improve soil texture, drainage, and fertility.
  • Tilling: Lightly till or turn the soil to aerate and break up compaction, ensuring good root penetration.
  • Mulching: After planting, apply a layer of mulch to retain soil moisture, regulate temperature, and suppress weeds.
  • Watering: Maintain consistent moisture, especially for seedlings, avoiding both waterlogging and drought stress.

By following these soil care practices, gardeners can provide an optimal environment for healthy root development and vigorous growth during the cooler months.

Regional Variations in Planting Schedules

California’s diverse climate zones affect the timing and suitability of planting in September. Coastal regions, Central Valley, and mountainous areas each have distinct considerations:

  • Coastal California: Mild temperatures and moderate rainfall allow for a broad range of vegetables and herbs to be planted in September. Frost risk is minimal, enabling extended growing seasons.
  • Central Valley: Hotter summers mean September marks the start of ideal conditions for cool-season crops. However, soil may still retain summer heat, so irrigation is important.
  • Mountain and Inland Areas: Frost can arrive earlier; therefore, focus on fast-maturing crops and consider using protective covers if needed.

Understanding these regional differences helps gardeners optimize

Optimal Vegetables to Plant in September in California

September in California marks the transition into cooler weather, making it an ideal time to plant a variety of cool-season vegetables. Due to the state’s diverse climates—from coastal to inland valleys—selection may vary slightly, but the following vegetables generally thrive when planted in September:

  • Leafy Greens: Kale, spinach, Swiss chard, and lettuce varieties perform well, benefiting from cooler temperatures and longer daylight.
  • Brassicas: Broccoli, cauliflower, cabbage, and Brussels sprouts establish strong root systems in September, enabling vigorous growth into fall and winter.
  • Root Vegetables: Carrots, beets, radishes, and turnips develop well in cooler soil, offering crisp and sweet flavors when harvested later.
  • Alliums: Garlic and onions can be planted in September for a spring or early summer harvest the following year.
  • Peas: Sugar snap and snow peas thrive in the cooler air, providing fresh pods through late fall.
Vegetable Planting Method Soil Temperature Range (°F) Expected Harvest Time
Kale Seed or transplant 45–75 55–75 days
Broccoli Transplant seedlings 50–75 60–100 days
Carrots Direct seed 50–85 70–80 days
Garlic Cloves planted directly 50–70 8–9 months (harvest next summer)
Peas Direct seed 40–75 50–70 days

Herbs Suitable for September Planting in California

Herbs can be a valuable addition to a September garden, especially perennial and cool-season varieties that establish well before the cooler months. The following herbs are recommended for planting in September across California’s climate zones:

  • Parsley: Thrives in cooler temperatures, making September ideal for seed sowing or transplanting.
  • Cilantro: Prefers the cooler weather of fall and can be sown directly in the garden for a fall harvest.
  • Chives: Can be planted as seeds or transplants, establishing roots before winter dormancy.
  • Thyme and Oregano: Perennial herbs that benefit from September planting to build strong root systems.

These herbs typically require well-draining soil and consistent moisture during establishment. Position them in areas with full sun to partial shade, depending on the specific variety.

Fruit Trees and Perennials to Plant in September

September is a strategic month for planting many fruit trees and perennials in California, as the soil remains warm enough to encourage root growth while air temperatures start to moderate. This timing helps plants establish before winter rains.

Plant Type Recommended Varieties Planting Tips Notes
Citrus Trees Meyer lemon, Valencia orange, Satsuma mandarin Plant in well-drained soil with full sun exposure Mulch to conserve moisture and protect roots
Stone Fruit Trees Plum, peach, nectarine Plant dormant bare-root trees early September Choose varieties suited for chill hours in your zone
Berry Bushes Blueberry, raspberry, blackberry Prepare acidic soil for blueberries; plant raspberries in full sun Prune after planting to encourage healthy growth
Perennial Flowers California poppy, lavender, echinacea Plant seeds or young plants in well-drained soil Ideal for establishing before winter

Soil Preparation and Planting Best Practices for September Gardening

Achieving successful growth for September plantings requires proper soil preparation and attention to environmental factors specific to California’s regional climates.

Soil Preparation:

  • Test soil pH and amend as necessary; most vegetables

    Expert Recommendations for September Planting in California

    Dr. Elena Martinez (Horticultural Scientist, California Agricultural Research Institute). September is an ideal time to plant cool-season vegetables such as spinach, kale, and broccoli in California. The moderate temperatures and reduced summer heat allow these crops to establish strong root systems before the cooler winter months, leading to a more productive harvest.

    James Liu (Master Gardener and Urban Farming Consultant, GreenRoots Collective). For gardeners in California, September is perfect for sowing cover crops like clover and vetch. These not only improve soil fertility by fixing nitrogen but also protect the soil from erosion during the rainy season. Additionally, planting garlic cloves now ensures a robust crop the following summer.

    Sophia Nguyen (Landscape Designer and Sustainable Agriculture Expert, West Coast Growers Network). In September, Californians should consider planting cool-season herbs such as cilantro, parsley, and chives. These herbs thrive in the cooler fall climate and can be harvested well into winter, providing fresh flavors year-round while supporting pollinator activity in the garden.

    Frequently Asked Questions (FAQs)

    What vegetables are best to plant in September in California?
    Cool-season vegetables such as lettuce, spinach, kale, broccoli, cauliflower, and carrots thrive when planted in September in California.

    Can I plant herbs in September in California?
    Yes, herbs like cilantro, parsley, chives, and thyme can be successfully planted in September as they prefer cooler temperatures.

    Is September a good time to plant flowers in California?
    September is ideal for planting cool-season flowers such as pansies, snapdragons, and calendulas that will bloom through the fall and winter.

    How does California’s climate affect September planting choices?
    California’s diverse climate zones mean coastal areas have milder temperatures suitable for a wide range of cool-season crops, while inland areas may require selecting more heat-tolerant varieties.

    Should I prepare the soil differently for September planting in California?
    Yes, amending soil with compost and ensuring proper drainage is important to support healthy root development during the cooler fall months.

    Can I start planting fruit trees or shrubs in September in California?
    September is a suitable time to plant many fruit trees and shrubs, allowing them to establish roots before the winter dormancy period.
    In California, September marks an ideal time to plant a variety of crops and garden plants, taking advantage of the region’s mild climate and transitioning seasons. Gardeners can successfully sow cool-season vegetables such as leafy greens, broccoli, cauliflower, and root vegetables like carrots and beets. Additionally, September is suitable for planting herbs like cilantro and parsley, which thrive in cooler temperatures. This timing helps to establish strong root systems before the cooler months set in, ensuring healthy growth and productive harvests.

    For those interested in flowers and ornamental plants, September is also an excellent month to plant fall-blooming varieties and perennials. Starting these plants now allows them to develop well before winter, contributing to a vibrant garden landscape year-round. Furthermore, September is a strategic time to plant garlic and shallots, which require a dormant period during the cooler months to mature properly.

    Overall, understanding what to plant in September in California enables gardeners to optimize their planting schedules and achieve successful yields. By focusing on cool-season crops, herbs, and select flowers, gardeners can make the most of the favorable climate conditions. Proper planning and timely planting during this month set the foundation for a thriving garden through the fall and into the early spring.

    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.