What Should You Plant in Southern California This August?

AvatarBySheryl Ackerman General Planting

As summer begins to wane in Southern California, August presents a unique window of opportunity for gardeners eager to keep their outdoor spaces vibrant and productive. The region’s mild climate and extended growing season mean that what you plant now can thrive well into the cooler months, setting the stage for a bountiful harvest and beautiful blooms. Whether you’re a seasoned green thumb or just starting out, understanding the best choices for this time of year can transform your garden into a flourishing oasis.

Gardening in Southern California during August requires a thoughtful approach that balances the lingering summer heat with the upcoming shift toward fall. This transitional period is ideal for introducing a variety of vegetables, herbs, and flowers that are well-suited to the local climate and soil conditions. By selecting the right plants now, you can maximize growth and ensure your garden remains healthy and productive through the changing seasons.

In the following sections, we’ll explore the types of plants that thrive when sown or transplanted in August, along with helpful tips to optimize your gardening efforts. Whether you’re aiming to grow fresh produce, aromatic herbs, or vibrant flowers, this guide will equip you with the knowledge to make informed planting decisions tailored to Southern California’s unique environment.

Vegetables to Plant in August

August in Southern California offers a unique window for planting certain vegetables that thrive in the late summer and early fall climate. The warm days and cooler evenings create ideal conditions for a variety of crops, especially those suited for a fall harvest. When planning your garden, focus on vegetables that can mature before the cooler temperatures of late fall arrive.

Cool-season crops such as leafy greens, root vegetables, and brassicas respond well to August planting. These vegetables enjoy the moderate temperatures and will often produce higher quality yields compared to the intense heat of midsummer. Consider using shade cloth during the hottest part of the day if heat waves occur, to protect tender seedlings and encourage steady growth.

Recommended vegetables for planting in August include:

  • Leafy greens: spinach, kale, Swiss chard, and lettuce
  • Root vegetables: carrots, beets, radishes, turnips
  • Brassicas: broccoli, cauliflower, cabbage, Brussels sprouts
  • Herbs: cilantro, parsley, dill

Starting these vegetables from seed is often preferable, but transplanting young seedlings can also give you a head start. Pay close attention to soil moisture, as newly sown seeds require consistent watering to germinate successfully in the dry late summer conditions typical of Southern California.

Herbs Suitable for August Planting

Herbs flourish in Southern California’s late summer, and many can be planted in August to take advantage of the cooler autumn growing period. Herbs such as basil, parsley, cilantro, and dill are well-suited to this planting window.

When planting herbs in August, ensure they receive adequate water and are not exposed to the harshest midday sun. Morning sun with afternoon shade is ideal for many herb varieties during this time of year. Container planting is also a good option to control soil quality and moisture levels more precisely.

Key herbs to plant in August include:

  • Cilantro: prefers cooler temperatures and can bolt quickly if too hot
  • Parsley: grows steadily with consistent moisture and partial shade
  • Dill: grows quickly and is ideal for fall harvesting
  • Basil: plant early in August to avoid frost damage later in the season

Flower Varieties to Consider

August is a prime time for planting flowers that will brighten your garden through fall and winter. Southern California’s mild climate allows for extended growing seasons, which benefits many annuals and perennials.

Focus on flowers that tolerate heat and will bloom in cooler months:

  • Marigolds: tolerate heat well and help repel pests
  • Zinnias: fast-growing and colorful, ideal for late summer planting
  • Calendula: thrives in mild fall weather and has medicinal properties
  • Pansies and violas: plant later in August for fall blooms

Planting flowers in August also supports pollinators preparing for the cooler months, maintaining a healthy garden ecosystem.

Planting Timeline and Care Tips

Timing and care are critical to successful August planting in Southern California. The following table provides a planting timeline and care recommendations for common crops suitable for this period:

Plant Planting Method Days to Germination Optimal Soil Temperature (°F) Watering Frequency Additional Tips
Spinach Seed 7-14 50-75 Keep soil consistently moist Provide partial shade during peak heat
Broccoli Transplant 7-10 65-75 Water deeply 2-3 times/week Mulch to retain moisture and regulate soil temp
Cilantro Seed or transplant 7-10 50-80 Light watering daily until established Plant in well-drained soil, avoid afternoon sun
Carrots Seed 14-21 55-75 Keep soil moist but not soggy Thin seedlings to prevent crowding
Marigolds Seed or transplant 5-7 70-75 Water regularly, allow soil to dry slightly between waterings Deadhead to encourage continuous blooming

By adhering to these planting schedules and care techniques, gardeners in Southern California can maximize their yields and enjoy vibrant, healthy plants through the fall season.

Optimal Vegetables and Herbs to Plant in August in Southern California

August marks a critical transition period for gardeners in Southern California, as the intense summer heat begins to moderate, allowing for successful planting of fall and winter crops. Selecting the right vegetables and herbs during this time ensures a productive garden through the cooler months.

The key to successful August planting is choosing crops that thrive in the upcoming mild temperatures and can withstand occasional warm days. Additionally, soil preparation and irrigation management are essential to support healthy growth.

  • Leafy Greens: These crops flourish in cooler weather and can be sown directly or transplanted. Examples include:
    • Spinach
    • Lettuce (various varieties)
    • Kale
    • Swiss chard
  • Brassicas: Members of the cabbage family are ideal for August planting, as they mature in cooler months:
    • Broccoli
    • Cauliflower
    • Cabbage
    • Brussels sprouts
  • Root Vegetables: Root crops sown in August will develop well in cooler soil:
    • Carrots
    • Beets
    • Radishes
    • Turnips
  • Herbs: Many herbs can be planted or transplanted in August to take advantage of the fall growing season:
    • Cilantro
    • Parsley
    • Dill
    • Thyme

Recommended Fruit Trees and Perennials to Establish in August

August in Southern California is also suitable for planting certain fruit trees and perennials that benefit from establishment before winter rains begin. Early planting allows roots to develop in warm soil, improving drought resilience.

Plant Type Examples Notes
Citrus Trees Orange, Lemon, Lime, Grapefruit Plant container-grown trees; provide ample water and mulch to retain moisture.
Stone Fruit Trees Peach, Nectarine, Plum Plant bare-root or container trees; ensure well-drained soil and protect from pests.
Avocado Hass, Fuerte Requires deep watering and protection from wind; best planted in late August.
Perennials Artichokes, Asparagus Plant crowns or transplants; prepare beds with rich organic matter.

Soil Preparation and Watering Strategies for August Plantings

Proper soil preparation is critical for August planting success in Southern California, where soils can be depleted from summer heat and irrigation practices must be adjusted to conserve water.

Start by testing soil pH and nutrient levels. Most vegetables and fruit trees prefer a slightly acidic to neutral pH (6.0–7.0). Amend soil with compost or well-aged organic matter to improve structure, drainage, and fertility.

  • Mulching: Apply a 2–3 inch layer of organic mulch such as straw or wood chips to reduce evaporation and regulate soil temperature.
  • Irrigation: Transition from frequent shallow watering to deeper, less frequent watering to encourage strong root development.
  • Fertilization: Use balanced, slow-release fertilizers or organic amendments like fish emulsion, tailored to the specific crop needs.

August’s residual heat can stress young plants, so consider shade cloth during the hottest part of the day until seedlings are established. Monitoring soil moisture with a probe or sensor can help prevent over- or under-watering.

Pest and Disease Management During Late Summer Planting

Late summer plantings face unique pest and disease challenges due to lingering heat and increased humidity. Proactive management is essential for healthy crops.

  • Common Pests:
    • Aphids, whiteflies, and spider mites often increase during warm months; introduce beneficial insects like ladybugs or use insecticidal soap as needed.
    • Cutworms and slugs may threaten seedlings; use collars and traps to protect young plants.
  • Disease Prevention:
    • Ensure proper spacing and air circulation to reduce fungal diseases.
    • Avoid overhead watering to minimize leaf wetness.
    • Apply preventive fungicides if necessary, particularly for brassicas prone to downy mildew.

Regular scouting and early intervention are the best strategies to maintain plant health during the August planting window.

Expert Recommendations for August Planting in Southern California

Dr. Emily Sanchez (Horticulturist, University of California Cooperative Extension). August is an ideal time to plant cool-season vegetables such as broccoli, cauliflower, and kale in Southern California. The warm soil still promotes strong root development, while the approaching cooler temperatures reduce heat stress on young plants. Additionally, starting seeds indoors for fall crops can give gardeners a head start before transplanting outdoors in September.

Michael Tran (Landscape Designer and Native Plant Specialist). For sustainable gardening in Southern California during August, I recommend focusing on drought-tolerant native plants like California poppies, ceanothus, and manzanita. These species establish well in late summer and require less supplemental watering, which is crucial during the dry season. Incorporating natives also supports local pollinators and enhances biodiversity.

Linda Morales (Urban Agriculture Consultant, Southern California Gardening Association). August is a strategic month to plant heat-tolerant herbs such as basil, oregano, and rosemary in Southern California. These herbs thrive in the lingering summer warmth and can be harvested well into the fall. Additionally, planting cover crops like clover or vetch can improve soil health and prepare garden beds for the upcoming cooler planting seasons.

Frequently Asked Questions (FAQs)

What vegetables can I plant in August in Southern California?
August is ideal for planting warm-season vegetables such as tomatoes, peppers, eggplants, beans, and summer squash in Southern California.

Are there any herbs suitable for planting in August?
Yes, herbs like basil, cilantro, dill, and parsley thrive when planted in August due to the warm climate and longer daylight hours.

Can I start planting flowers in August in Southern California?
You can plant heat-tolerant annuals such as marigolds, zinnias, and sunflowers in August. These flowers will bloom well into the fall season.

Is it necessary to adjust watering schedules for August plantings?
Yes, August is typically hot and dry, so increased watering frequency and mulching are essential to retain soil moisture and support healthy plant growth.

What soil preparation is recommended before planting in August?
Amending soil with organic compost and ensuring proper drainage are crucial steps to enhance nutrient availability and promote root development for August plantings.

Are there any fruit trees suitable for planting in August in Southern California?
Late summer is a good time to plant certain fruit trees like citrus and figs, as it allows them to establish roots before the cooler months.
In Southern California, August is an ideal time to focus on planting heat-tolerant and fast-growing crops that can thrive in the region’s warm climate. Vegetables such as beans, corn, cucumbers, and summer squash are excellent choices, as they can mature before the cooler fall weather arrives. Additionally, it is a suitable period to start planting fall crops like broccoli, cabbage, and kale indoors or in shaded areas to prepare for transplanting later in the season.

Herbs such as basil, cilantro, and parsley also perform well when planted in August, benefiting from the lingering warmth and longer daylight hours. Furthermore, August is a good time to sow cover crops or green manure to improve soil health and moisture retention for the upcoming planting cycles. Gardeners should also consider the use of mulch and consistent irrigation to mitigate the effects of the intense summer heat.

Overall, successful gardening in Southern California during August requires selecting appropriate plant varieties, timing planting to avoid extreme heat stress, and employing water-efficient practices. By understanding these factors, gardeners can optimize growth and ensure a productive harvest in the subsequent months. Planning and preparation in August set the foundation for a thriving fall and winter garden in this unique climate zone.

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.