How to Start Tomato Plants Indoors From Seeds

Tomatos have a greater chance of survival when started indoors.

Starting tomato seedlings indoors gives you a head start on the planting season. Tomato seeds can be started in containers while the weather outdoors is still cool and transplanted to an outdoor garden in the summer. Indoor care for the tomato plants while they begin to grow will also limit their chances of early disease or death due to cold temperatures or insects. Even without a green thumb, beginning tomato plants in your home is easy with fruitful results.

Things You'll Need

• Tomato seeds
• Potting soil
• Seedling tray with multiple sections
• Watering can
• Water
• Fluorescent light (optional)

Instructions

1. Plan to sow tomato seeds indoors at least six weeks before your region's last frost date--when nighttime temperatures no longer drop below 55 F. The date varies by area of the country, but is generally in mid-February or March for Southern states and mid-April or May for Northern states.

2. Fill the seedling tray sections with potting soil within 1/2 inch of the tray's rim. Fill the watering can with water and water the soil so it is thoroughly damp but not soaked.

3. Make a 1/4-inch-deep hole in the soil with your finger or a pencil in each of the tray's sections. Drop two or three tomato seeds together in the holes. Sowing several seeds together increases your chances of successful germination. Cover the seeds lightly with soil to the original soil level. The seeds should be under 1/4 inch of soil.

4. Place the seedling tray in a warm location. The best temperature for germination is between 70 and 80 F, so on top of a running refrigerator or near a sunny window are good locations.

5. Move the tray into a location where it receives full daylight after the seedlings sprout in five to 10 days. If you have no sunny window ledges, a hanging fluorescent light placed directly over the seedling tray can provide the light and warmth the plants need to grow.

6. Water the tray when the top soil appears dry. Too much water can stall or stop germination, so it is important that the soil be moist but never soggy. Continue to care for the plants indoors until they are at least 6 inches tall and ready for transplant outside.

Tips & Warnings

• A sheet of clear plastic wrap over the seedling tray can help retain moisture and act as a greenhouse to keep the tray warm.

• Use a spray bottle or mister to control the amount of water given to the plants.

• Starting seedlings too soon before summer planting season will shorten the harvest season.

References

• University of Illinois Extension: Starting Seeds Indoors
• Park Seed Growing Journal: Growing Tomato Plants From Seed