From Seed to Soil: Summer

BY Kenise Adams
June 22, 2026

Attractions

Photography by iStock/Smitt

What to propagate in summer for fall harvest

As the summer temperatures rise, it’s time to turn your attention to seeds that will thrive in the extended heat of San Diego’s fall season. Whether you’re an experienced gardener or just getting started, there are plenty of plants that will add flavor, color, and texture to your garden as summer plantings. According to Brijette Peña of the San Diego Seed Company, “Summer gardening is all about choosing crops that can withstand the heat and produce flavorful yields.”

With our temperate climate, there’s a wide array of crops to start in what some gardeners consider an offseason for new starts. With expert guidance from Peña, you can cultivate a garden that offers fresh produce through summer into fall. Remember to mulch, water deeply, and enjoy the beauty and bounty of your summer garden. If you’re eager to delve deeper into seasonal planting and seek seeds tailored for our 9–10 zones as well as growing tips, visit Peña’s website at sandiegoseedcompany.com to find a comprehensive growing calendar and a plethora of resources to support your gardening journey.

Let’s explore garden staples like marjoram, peppers, and tomatoes—each offer unique qualities that will help your garden flourish during the hottest months of the year.

Start these seeds to summer to harvest and enjoy in the fall

Sweet Marjoram

With its sweet, oregano-like flavor, marjoram is a perfect addition to your herb garden. It grows well in zones 9–10, offering fresh foliage throughout the summer.

Getting started

Sprinkle seeds on moist soil and press them gently into the surface.
Transplant seedlings once they’re 4–5 inches tall, spacing them 12 inches apart.
Keep plants weed-free and water regularly to encourage strong growth.

Marjoram loves full sun and well-drained soil. It’s great in containers, making it easy to move during extreme heat. Harvest leaves just before flowering for the best flavor, and prune plants periodically for a continuous harvest.

Peppers

Peppers, offering a wide range of flavors from sweet to fiery hot, are a must-have in any garden. Peppers grow well in full sun and are ideal for zones 9–10.

Getting started

Start seeds in spring or in the early part of the summer season.
Use starter pots for germination, then transplant when seedlings are 4–5 inches tall.
Space plants 18 inches apart to ensure they have enough room to grow.
In extreme heat, use shade cloth to prevent sunscald.

Pepper plants produce an abundance of fruits. Whether you’re growing bell peppers, jalapeños, or habaneros, regular harvesting encourages more fruit production.

Tomatoes

Tomato plants flush with fruit. Image: iStock/yagmradam.

Tomatoes are the most popular staple among home gardeners, and for good reason: With over 10,000 varieties to choose from, tomatoes are versatile and offer endless culinary possibilities. “In zones 9–10, tomatoes can be grown year-round, but they thrive in the warmth of the summer months,” noted Peña.

Getting started

Plant determinate varieties in small spaces and indeterminate varieties with trellises for support.
Space plants 18 inches apart for optimal airflow.
Keep the soil moist and mulch to retain moisture.

Tomatoes are best harvested when ripe, and picking them regularly ensures a steady supply throughout the growing season. Eat them in fresh salads, salsas, and homemade sauces.

From the Pages

Originally published in issue 78.

Kenise Adams

Kenise Adams is a freelance writer specializing in raw vegan and living whole foods. Kenise has interviewed California farmers for Edible San Luis Obispo and Edible San Diego and written e-books on juicing, gut cleansing, and raw vegan recipes.