If you’re a gardener in Southern California, figuring out when to plant broccoli can be the key to a great harvest. This guide will walk you through the optimal planting season guide for this cool-weather favorite.
Our unique climate, with its mild winters and long growing periods, offers two fantastic chances to grow broccoli each year. Getting the timing right means you’ll get those perfect, tight heads before the heat or cold interferes. Let’s get your garden schedule sorted.
When to Plant Broccoli in Southern California – Optimal Planting Season Guide
Broccoli thrives in cool weather, making it ideal for our region. The goal is to have the plants maturing when temperatures are between 65°F and 75°F. Southern California’s prime broccoli seasons are fall and late winter/early spring.
The Two Main Planting Windows
You have two main options for planting. Each has its own advantages.
- Fall Planting (Late Summer Start): This is often the most successful crop. You start seeds indoors or plant transplants in late July to August. The plants grow through the fall and are ready for harvest in late fall or early winter.
- Spring Planting (Late Winter Start): For a spring harvest, you’ll need to start seeds indoors or plant transplants in January or February. The trick is to get them established so they can produce heads before the late spring heat arrives.
Detailed Monthly Planting Calendar
This calendar is a guideline. Microclimates vary, so adjust based on your specific location.
For a Fall Harvest
- June – July: Begin planning. Order seeds if needed.
- Late July – August: Start seeds indoors or in a shaded nursery area. The summer heat can be harsh on seedlings.
- September – Early October: Transplant seedlings into the garden. This is the ideal outdoor planting time as soil begins to cool.
- November – December: Primary harvest period for fall-planted broccoli.
For a Spring Harvest
- December – January: Start seeds indoors where they can get plenty of light.
- Late January – February: Transplant sturdy seedlings into the garden. Protect them if an unexpected frost is forecasted.
- March – April: Keep plants well-watered as temperatures begin to rise.
- April – May: Harvest your spring broccoli before summer heat causes bolting (flowering).
Choosing the Right Variety for Our Climate
Some broccoli types handle our conditions better than others. Look for heat-tolerant and fast-maturing varieties to beat the warm weather.
- Calabrese: A classic, reliable heirloom type.
- Green Goliath: Tolerates warmer weather well and produces side shoots.
- Packman: A fast-maturing hybrid, excellent for spring planting.
- Broccoli Raab (Rapini): Actually a different plant, but it grows very well here and is harvested for its leaves and small buds.
Step-by-Step Planting Guide
Follow these steps for sucessful broccoli.
1. Starting from Seed
Begin seeds in small pots or trays filled with a seed-starting mix. Plant seeds about ¼ inch deep. Keep the soil consistently moist and in a bright location. Seeds germinate best at around 70-80°F.
2. Preparing Your Garden Bed
Broccoli needs full sun (at least 6 hours) and rich, well-draining soil. Work in 3-4 inches of compost or well-rotted manure before planting. The soil pH should be slightly acidic to neutral (6.0-7.0).
3. Transplanting Seedlings
When seedlings have 4-6 true leaves, they are ready to harden off and transplant. Space plants 18-24 inches apart in rows that are 2-3 feet apart. This gives them room to grow big and healthy.
4. Watering and Feeding
Water deeply and regularly, especially as heads begin to form. Inconsistent watering can lead to poor head development. Use a balanced, organic fertilizer when transplanting and again when heads start to form. Avoid high-nitrogen fertilizers later in growth, as they encourage leaf growth over head growth.
Common Challenges and Solutions
Every garden faces problems. Here’s how to handle common broccoli issues in SoCal.
Pests
- Aphids: Blast them off with a strong spray of water or use insecticidal soap.
- Cabbage Loopers/Worms: Handpick them or use an organic Bt (Bacillus thuringiensis) spray.
- Snails and Slugs: Use beer traps or iron phosphate bait around plants.
Bolting
Bolting is when the plant sends up a flower stalk, making the head bitter. It’s triggered by temperatures that are too warm. The best prevention is strict adherence to the planting windows outlined above. If a plant bolts, harvest it immediately—the leaves and stems are still edible.
Poor Head Formation
Small or loose heads can result from stress—too much heat, too little water, or lack of nutrients. Ensure consistent care and choose the right variety for the season.
Harvesting Your Broccoli
Harvest is the best part. Cut the central head when the buds are tight and dark green, before the yellow flowers start to open. Use a sharp knife and make a clean, angled cut about 5-6 inches down the stem.
After the main head is harvested, many varieties will produce smaller side shoots for several weeks. Keep watering and you’ll get a continuous, though smaller, yield.
FAQs: Growing Broccoli in Southern California
Can I grow broccoli year-round in Southern California?
Not quite. While our winters are mild, summer heat makes it nearly impossible. The two-season approach (fall and late winter/spring) is your best bet for quality heads.
What if I missed the fall planting window?
You can try planting transplants in early fall, but they may not reach full size. Alternatively, focus on preparing for the spring planting window. You can also try growing broccoli raab, which is more forgiving on timing.
How do I protect broccoli from a rare frost?
Young transplants are most vulnerable. Cover them with frost cloth or a lightweight row cover overnight. Mature broccoli plants can handle a light frost, which can even improve their flavor.
Why are my broccoli leaves turning yellow?
Yellowing leaves can be a sign of several issues: overwatering, underwatering, or a nitrogen deficiency. Check your soil moisture first and adjust your watering schedule. A side dressing of compost can help if it’s a nutrient issue.
Can I plant broccoli directly in the ground from seed?
You can, but starting seeds indoors gives you more control over the delicate seedling stage, especially during hot late summer or cool late winter weather. Direct sowing works better for the fall planting window if you can provide consistent moisture and some shade for the young seedlings.
Growing broccoli in Southern California is incredibly rewarding when you sync your gardening with the optimal seasons. By following this planting guide, you’ll maximize your chances of a bountiful harvest of crisp, homegrown broccoli. Remember, the secret is in the timing—let the mild coastal and inland climates work for you, not against you. With a little planning, you’ll be enjoying your own fresh broccoli while others are waiting for theirs to grow.