Tomato Growing Guide: How to Grow Tomatoes from Seed

Tomatoes are one of the most popular vegetables for home gardeners. They are grown for fresh eating, slicing, sauces, canning, salads, and specialty uses. With proper seed starting, sunlight, soil, and watering, tomatoes can produce heavily throughout the warm growing season.

Quick Tomato Growing Facts

When to Start Tomato Seeds

Start tomato seeds indoors about 6 to 8 weeks before your expected last spring frost. Tomatoes need warm soil to germinate and should not be transplanted outdoors until danger of frost has passed and night temperatures are consistently above 50°F.

How to Plant Tomato Seeds

Sow tomato seeds about 1/4 inch deep in a quality seed-starting mix. Keep the soil evenly moist but not soggy. A warm location or seedling heat mat can improve germination. Once seedlings emerge, place them under bright light to prevent stretching.

Transplanting Tomato Seedlings

Before planting outdoors, harden off tomato seedlings for 7 to 10 days by gradually exposing them to outdoor conditions. Transplant into the garden after frost danger has passed. Tomatoes may be planted deeply because roots can form along the buried stem, creating a stronger plant.

Sunlight and Soil Requirements

Tomatoes grow best in full sun with fertile, well-drained soil. Add compost or aged organic matter before planting. Avoid planting tomatoes in heavy, poorly drained soil, as wet roots can lead to poor growth and disease problems.

Watering Tomatoes

Water tomatoes deeply and consistently. Irregular watering can cause stress, cracking, and blossom-end rot. Water at the base of the plant when possible and avoid wetting the foliage, especially late in the day.

Fertilizing Tomatoes

Tomatoes benefit from balanced fertility. Too much nitrogen can produce large leafy plants with fewer fruits. Once flowering begins, use a fertilizer that supports fruiting and root development.

Supporting Tomato Plants

Many tomato varieties need support from cages, stakes, or trellises. Indeterminate tomatoes continue growing and producing over a long season and usually need strong support. Determinate tomatoes grow to a more compact size and often produce a concentrated harvest.

Common Tomato Problems

When to Harvest Tomatoes

Harvest tomatoes when fruits are fully colored, firm, and slightly soft to the touch. For best flavor, allow tomatoes to ripen on the plant when possible. If frost threatens, mature green tomatoes can be picked and ripened indoors.

Best Uses for Tomatoes

Tomatoes are used fresh, sliced, cooked, canned, dried, and made into sauces, salsa, juice, and paste. Cherry tomatoes are excellent for salads and snacking, while paste tomatoes are preferred for sauces and processing.

Tomato Variety Index

Explore Seedman's tomato seed varieties, including heirloom tomatoes, hybrid tomatoes, cherry tomatoes, paste tomatoes, beefsteak tomatoes, container tomatoes, heat-tolerant tomatoes, and tomatillos.

Shop all tomato seeds at Seedman.com

Tomato Growing Summary

To grow tomatoes successfully, start seeds indoors in warm conditions, provide strong light, transplant after frost, plant in full sun, water consistently, and support plants as they grow. With good care, tomatoes can be one of the most productive and rewarding crops in the home garden.