Growing Tomatoes and Peppers From Seed

Tomatoes and peppers are the stars of most vegetable gardens, and growing them from seed opens up hundreds of varieties: tiny cherry tomatoes, huge heirloom slicers, sweet bell peppers and fiery jalapeños. Both crops are started indoors, but they have slightly different needs.

Timing

• Peppers: start 8–10 weeks before your last frost. They grow slowly at first.
• Tomatoes: start 6–8 weeks before your last frost. They grow fast; starting too early produces leggy plants.

Germination

Sow seeds about ¼ inch deep in moist seed-starting mix. Warmth is key:

• Tomatoes germinate in 5–10 days at 70–80°F (21–27°C).
• Peppers can take 7–21 days and germinate best at 80–85°F (27–29°C). A seedling heat mat helps a lot. Hot peppers are often the slowest.

Light and airflow

Move seedlings under bright light the moment they emerge. Run a small fan on low for a few hours a day; the gentle movement makes stems thicker and stronger.

Potting up

When seedlings have two sets of true leaves, transplant them into 3–4 inch pots. Bury tomato stems up to their first leaves — tomatoes grow roots along the buried stem, giving them a stronger root system. Peppers should be replanted at the same depth.

Feeding

Once true leaves appear, feed every week or two with a diluted, balanced liquid fertilizer at quarter to half strength.

Moving outside

Both crops are frost-tender and stall in cold soil. Wait until nighttime temperatures stay above 50°F (10°C), then harden off seedlings over a week before transplanting. Peppers in particular sulk in cold soil, so it is better to plant a week late than a week early.

In the garden

• Give them full sun — 8 hours is ideal.
• Space tomatoes 18–36 inches apart depending on variety, and stake or cage them at planting time.
• Space peppers 12–18 inches apart.
• Water deeply and consistently. Uneven watering causes blossom end rot in both crops.
• Mulch to keep soil moisture steady.

Harvest tip

Jalapeños can be picked green or left to ripen red for a sweeter, hotter flavor. Tomatoes ripen best on the vine, but can finish ripening on the counter if frost threatens.

Find heirloom peppers, tomatoes and more in our vegetable seed collection.