How to Start Tomato & Pepper Seeds Indoors


Sometimes it's hard to wait for the weather to warm up enough to plant your summer vegetable garden. You can get a headstart on the season if you start the seeds of some vegetables indoors, such as tomatoes and peppers. Tomatoes and peppers of all types are related to one another---they belong to the nightshade plant family, which also includes eggplant and potatoes. Tomato and pepper seeds are good choices for starting indoors before the final spring frost. They both require the same type of conditions so you can start them in the same area, with the same care.

Step 1

Fill your flats with potting soil and then water them to make the soil moist. Using your pencil, dig quarter-inch deep, straight furrows and then drop your tomato or pepper seeds about 1/2 inch apart. Cover the furrows with potting soil and then label the type of plant in each flat.

Step 2

Place your flats in an indoor area where the temperature remains at least 75 degrees Fahrenheit at all times. Heated plant mats are available for sale---if you choose this method it will prevent you from needing to heat an entire room. Also provide your flats with sufficient light---tomatoes and peppers need as much as 18 hours a day of direct sunlight or artificial light, so supplement the natural light your room receives by hanging one or more fluorescent shop lights or "grow lights" above your flats.

Step 3

Continue watering your flats after you see germination begin. Under the correct conditions, tomato and pepper seeds will germinate within one week to 10 days of planting. Also continue to give your seedlings 18 hours of light each day.

Step 4

Transplant your seedlings to individual pots when they are about a month old, or about 1 inch tall. Fill 3- or 4-inch nursery pots with the same type of potting soil you used for your flats. Water them well. Carefully remove the strongest, largest seedlings with a dinner fork, gently untangling any roots that are attached to neighboring seedlings.

Step 5

Hold each young plant by its leaves rather than its stem to prevent breakage and then set each one into a hole in its own small pot. If your seedlings are "leggy" (too tall), you can bury a portion of the stem. Water your pots well and continue to keep them under lights in a room where the temperature is always above 65 degrees.

Step 6

Plant your young plants outdoors when they are several inches tall and after the final spring frost. Wait until the nighttime temperature doesn't drop below about 55 degrees. Tomatoes and peppers both need rich, well-drained soil.

Things You'll Need

  • Nursery flats
  • Potting soil
  • Pencil
  • Fluorescent light(s) (optional)
  • Heating mat (optional)
  • Small nursery pots
  • Fork


  • Renee's Garden: Starting Tomato Seeds Indoors
  • Pepper Joe's: Starting Hot Pepper Plants From Seed

Who Can Help

  • Home Harvest Garden Supply: Seedling Propagation/Bottom Heat
Keywords: tomato pepper, vegetables growing, starting seeds

About this Author

Barbara Fahs lives on Hawaii island, where she has created Hi'iaka's Healing Herb Garden. Fahs wrote "Super Simple Guide to Creating Hawaiian Gardens," and has been a professional writer since 1984. She contributes to Big Island Weekly, Ke Ola magazine, GardenGuides and eHow. She earned her B.A. at UCSB and her M.A. from San Jose State University.