When Do You Plant Tomatoes In California

If you’re wondering when do you plant tomatoes in California, you’ve come to the right place. The answer isn’t a single date, but with this guide, you’ll know the perfect timing for your specific backyard.

California’s long growing season is a huge advantage. But its diverse climates mean timing is everything. Planting at the right moment leads to healthier plants and a bigger harvest.

Let’s break it down by region so you can get those tomatoes in the ground with confidence.

This is the core question. The general rule for most of California is to plant tomatoes after the last spring frost date. Tomatoes are heat-lovers and frost will kill them.

However, “spring” means different things across the state. Coastal areas have a long, cool spring. Inland valleys heat up fast. And desert regions have two distinct planting windows.

Your local microclimate matters too. A sunny, south-facing wall creates a warmer spot than an open, windy field. Always observe your own garden’s conditions.

California’s Climate Zones and Tomato Timing

California has several major climate zones that dictate planting schedules. Here’s a simple breakdown:

Coastal (San Francisco, Los Angeles, San Diego): Mild summers with fog. Plant from late March through May. You can often succession plant into early summer for a fall harvest.
Inland Valleys (Sacramento, San Joaquin): Hot, dry summers. Aim for early April to early May. Planting too late exposes fruit to extreme heat during setting.
Desert (Palm Springs, Imperial Valley): Very hot summers. Plant in late February to early March for a spring crop, or again in late August for a fall crop.
Mountain & Northern Regions: Shorter seasons with frost risk. Wait until late May or even early June. Use season-extending techniques like Wall O’ Waters.

Understanding Your Last Frost Date

This is your key calendar marker. The last frost date is the average final day in spring when a light freeze can occur.

You can find estimates online for your zip code. But treat them as a guide, not a guarantee. A warm spring might mean an earlier safe date, while a cold snap can push it back.

A good strategy is to watch the 10-day forecast as your target date approaches. If nights are consistently above 45°F, you’re likely safe. Soil temperature is also crucial—tomatoes prefer soil above 60°F.

Starting Seeds vs. Buying Transplants

Most gardeners use transplants from a nursery. This gives you a head start. For transplants, simply follow the outdoor planting dates for your zone.

If you start from seed indoors, you need to work backwards:

Find your optimal outdoor planting date (e.g., April 15).
Subtract 6 to 8 weeks for growing the seedling. That’s your seed-starting date (e.g., late February).
Start seeds in trays indoors with plenty of light. Don’t let them get leggy.

Starting seeds allows you to grow unique heirloom varieties you won’t find in stores. It’s very rewarding to see the whole process through.

Step-by-Step Planting Guide

Once your date arrives, here’s how to plant for success:

Choose a Sunny Spot: Tomatoes need at least 6-8 hours of direct sun. More is better.
Prepare the Soil: Amend planting holes with compost. Tomatoes are heavy feeders. Ensure good drainage.
Plant Deeply: Bury the stem up to the first set of true leaves. This encourages a stronger root system along the buried stem.
Water Well: Give them a thorough soak after planting to settle the soil.
Add Support: Install cages or stakes right away to avoid damaging roots later.
Mulch: Apply a layer of straw or wood chips to retain moisture and suppress weeds.

A Note on Watering and Fertilizing

Water deeply and consistently, especially once fruit appears. Irregular watering leads to blossom end rot. Drip irrigation is ideal.

Fertilize at planting with a balanced organic fertilizer. Then, switch to a lower-nitrogen, higher-phosphorus formula when flowering begins to promote fruit, not just leaves. Too much early nitrogen can cause lush growth but few tomatoes.

Special Considerations for Fall Tomatoes

In many parts of California, you can grow a second crop for fall harvest. This is especially true in coastal and inland valleys.

The trick is to time it so fruit matures before the first fall frost and cooler, shorter days. Calculate by:

Finding your average first fall frost date.
Counting back the “days to maturity” on your seed packet or transplant tag.
Adding an extra 2-3 weeks for slower growth as days shorten.

For a fall crop, you often need to start seeds indoors in mid-summer, as nurseries may not carry transplants then. Provide shade for young seedlings during the hottest part of the afternoon.

Common Mistakes to Avoid

Even experienced gardeners can make these errors. Here’s what to watch for:

Planting Too Early: Impatience leads to stunted or frost-damaged plants. Warm the soil with black plastic if your eager.
Overcrowding: Give plants plenty of space for air circulation. This prevents fungal diseases.
Ignoring Crop Rotation: Don’t plant tomatoes in the same spot year after year. It depletes soil and encourages disease.
Forgetting to Harden Off: If you start plants indoors, acclimate them to outdoor sun and wind over 7-10 days before planting.

Recommended Tomato Varieties for California

Some varieties perform exceptionally well here. Consider these types:

For Coastal Climates: Choose heat-loving varieties that tolerate cooler nights. ‘Early Girl’, ‘Sungold’, and ‘Stupice’ are reliable.
For Hot Inland Valleys: Look for heat-setting and crack-resistant types. ‘Celebrity’, ‘Solar Fire’, and ‘Arkansas Traveler’ are great choices.
For Containers: Patio or determinate varieties like ‘Bush Early Girl’, ‘Patio Choice Yellow’, and ‘Tumbling Tom’ work well in pots.

Experiment with a few different kinds each season to see what thrives best in your unique garden.

FAQ: Your Tomato Planting Questions Answered

What is the best month to plant tomatoes in Southern California?
In coastal Southern California, plant from March through May. In hotter inland areas (like Riverside), aim for early April. Desert areas plant in late February or late August.

Can I plant tomatoes in July in California?
In cooler coastal zones, yes, for a fall harvest. In hot inland and desert areas, July is generally too hot for planting; wait for the fall planting window in late August.

How late is too late to plant tomatoes?
It depends on your first frost date. Tomatoes need 60-100 frost-free days to produce, depending on the variety. Count backwards from your first expected frost to find your latest safe date.

Should I plant tomatoes in full sun?
Absolutely. They require a minimum of 6 hours, but 8 or more is ideal for the best flavor and yield. In extremely hot desert areas, some afternoon shade can prevent scalding.

What do you put in the hole when planting tomatoes?
Mix compost into the native soil. You can also add a handful of balanced organic fertilizer or a specific tomato food, following package instructions. Some gardeners use crushed eggshells for calcium.

By following these regional guidelines and tips, you’ll maximize your chances for a succesful and bountiful tomato season. The perfect timing, combined with good care, is the secret to those sweet, homegrown flavors you just can’t buy. Remember, gardening is a learning process, so take notes each year and adjust as you go.