When to Plant Tomatoes in Seaside, CA
Published: April 21, 2026
Tomato Planting Dates for Seaside, CA
| Start seeds indoors | February 1–8 |
| Last frost (average) | March 15 |
| Transplant outdoors | March 29–April 8 |
| Minimum soil temperature | 60°F |
| Expect first harvest | May 28 – June 22 |
| Fall crop planting | August 23–September 2 |
| Fall crop harvest | October 22 |
| First fall frost (average) | November 15 |
⚠ Warm-climate gardeners (TX, FL, AZ) can grow TWO crops: spring (Feb–March transplant) and fall (July transplant for October harvest).
Best Tomato Varieties for Seaside, CA
For Zone 7a Seaside, the best-performing tomato varieties are Big Beef, Early Girl, and Better Boy — all widely adapted, disease-resistant varieties proven across the transition zone. Cherokee Purple is a good alternative where disease resistance matters most, especially in humid summers. These varieties are typically stocked by local nurseries and are the safest bets for gardeners new to tomato in Seaside.
Growing Tomatoes in Seaside
Seaside sits in Zone 7a, with an average last frost of March 15 and first fall frost around November 15 — giving a 245-day frost-free growing season. Warm-season crops like tomato need soil at 60°F or above before transplanting; Seaside's frost calendar puts that window clearly in the late-spring to early-fall range.
Seaside's moderate climate supports tomato on the standard transplant calendar with minimal special accommodation. Succession planting — sowing fresh seeds or setting new transplants every 2–3 weeks through spring — stretches the harvest window and gives you a backup crop if pests hit the first planting.
Seaside's Zone 7a is classic transition territory for tomato. The season is long enough for a full warm-season crop without needing aggressive indoor starting — 6 weeks before last frost is enough for most varieties. Late frosts are the main risk; keep row cover available until 2 weeks after your average last frost.
Seaside's mixed soil conditions vary block by block — get a soil test if you have not in three years. Generally, a base of quality compost (2 to 3 inches annually) and consistent watering at 1.5 inches per week serves tomato well across most soil types found in Seaside.
Tomato Calendar for Seaside
| Month | Task |
|---|---|
| February | Start seeds indoors under grow lights |
| March | Transplant outdoors into warm soil |
| May | Expect first harvest window to open |
| August | Start fall crop — transplants or direct sow |
| November | First fall frost — harvest remaining, end of outdoor season |
Tomato Tips for Seaside Gardeners
- •Bury the stem 2/3 deep when transplanting — roots grow from the buried stem for a stronger plant.
- •Consistent watering prevents blossom end rot and fruit cracking; uneven moisture causes both.
- •Succession plant tomato in Seaside every 2–3 weeks through spring to extend the harvest window into summer.
Common Tomato Pests in Seaside
- •Tomato Hornworm — peaks July in Zone 7a (active May–September); look for 3–4 inch green caterpillars with white stripes; handpick into soapy water or apply Bt spray.
- •Aphids — peaks July in Zone 7a (active May–September); clusters on leaf undersides; blast with a strong water spray or apply neem oil.
- •Early Blight — peaks July in Zone 7a (active May–September); dark rings on lower leaves; remove affected leaves and apply copper fungicide.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Tomatoes in Seaside
In Seaside's moderate climate, Basil and Marigold are the most beneficial plants to grow alongside tomato. Basil repels whiteflies, aphids, and spider mites, and is planted at the same time as its partners. Keep tomato away from Potato — it competes for nutrients and shares blight diseases.
Frequently Asked Questions
When should I plant tomato in Seaside, CA?
In Seaside (Zone 7a), start tomato seeds indoors around February 1–8 and transplant outdoors around March 29–April 8. The city's average last frost of March 15 is the anchor date — count 6 weeks back for seed starting and 2 weeks forward for transplanting.
What zone is Seaside, CA for tomato growing?
Seaside is USDA Zone 7a. For tomato, this means a frost-free growing season of roughly 35 weeks running from March 15 to November 15. This is a comfortable window for warm-season crops like tomato — standard varieties work well.
When is tomato harvest season in Seaside?
Expect the first tomato harvest in Seaside around May 28, with harvest continuing through June 22. This is based on 60–85 days from transplant or direct sow. A fall crop planted August 23–September 2 adds a second harvest around October 22.
How long does it take to grow tomato in Seaside, CA?
From transplant or direct sow to first harvest, tomato takes 60–85 days in Seaside's climate. Based on a typical planting date of March 29–April 8, expect your first harvest around May 28. Seaside's Zone 7a transition-zone climate produces maturity times right in the middle of the stated range.
What soil does tomato need in Seaside?
Seaside's soil conditions vary block by block. Before planting tomato, do a soil test (most state extension offices run them for $15–30). The test reveals pH, key nutrient levels, and organic matter content, so you can amend appropriately rather than guessing. Generally, 2–3 inches of compost annually improves most soils for vegetable production.