Growing and Saving the Seed Of Green Tomatoes

Perhaps no heirloom crop inspires quite so much feeling among gardeners as tomatoes. They are the jewels of the summer garden. Tomatoes grow in an endlessly dazzling range of sizes, shapes, colors, and flavors, making them the most popular garden crop of the last 200 years. Tomato plants are either determinate or indeterminate. Determinate varieties stop their shoot production once the flower forms and set most of their fruit early. The plants are bushier and can be better contained, making them a good choice for small garden spaces. 

Indeterminate varieties will form flowers along the sides of the shoots but continue to grow. Indeterminates typically set fruit longer and need more space to grow. Gardeners often manage them with pruning and trellising.  All the varieties we sell are believed to be indeterminate unless specified as determinate. The best-tasting varieties tend to be heirloom and indeterminate. 



The wild progenitor of tomato is thought to have originated in the Andes Mountains of Peru and Ecuador, and domesticated in pre-Columbian Mexico. Its name comes from the Nahuatl (Aztec) word ‘tomatl.’ Tomatoes made their way to Europe in the early 16th century. While Spain and Italy adopted it into their foodways, in other places (such as northern Europe) tomatoes, as a member of the nightshade family, were believed to be poisonous and grown as ornamental plants only. The Spanish distributed the crop worldwide through their trade and colonies in the Caribbean and the Philippines, from which the crop spread to the Asian mainland. Tomatoes were grown in the U.S. starting in the Carolinas, possibly appearing there from the Caribbean. Thomas Jefferson grew and ate them. Modern breeding work began only in the late 1800s, beginning with Alexander Livingston, an early seedsman who released ‘Paragon’ in 1870.


  • Ornamental and culinary




  • As a tropical crop, tomatoes need plenty of warm weather and a long growing season. (Days-to-maturity figures count the time to first harvest from setting out transplants, which in turn take 6-8 weeks to grow before reaching transplant size.)
  • In long-summer climates, they may be direct sown as soon as frost is past, but most gardeners start the tiny seeds indoors 6-8 weeks before the last spring frost date.
  • Either way, the seeds are just barely covered and germinate most rapidly in temperatures of 70 and above—80 degrees is best. (Use a heating mat indoors if necessary.) 




  • Once the sprouts appear, they require good light to grow well.
  • They may need to be fed once or twice to make good growth prior to transplanting outdoors, which happens after last frost.
  • Tomatoes tolerate a wide range of soil conditions but do best in deep rich soil and in full sun.
  • Plants are usually staked but may be allowed to sprawl; spacing depends upon variety and which method is to be used.
  • Staked plants can be grown 18” apart in rows 3 or more feet apart; space 2-3 feet apart in rows 4 feet apart if the vines will be allowed to sprawl.
  • Determinate plants are usually smaller, requiring less space, and often need less support than indeterminate varieties.


  • Soil should be amended with plenty of compost; a little bone meal or other calcium source wards off blossom-end rot.
  • Hornworms can be controlled by daily hand picking; chickens love them. Hornworms are excellent camouflage artists, but their presence is marked by their excrement, which looks like small grenades. 
  • Pest control through “hiding” tomatoes in a polyculture planting can also be effective. Plant them with chili peppers, marigolds, borage, chives, nasturtiums, basil, calendula, sage, onions and garlic.

  • It is also useful to keep tomato plants as far away from each other as practical in the garden.

  • If you find a hornworm that appears to have grains of white rice glued to its sides, it’s been parasitized, and that means the beneficial Braconid wasps have arrived to the rescue! Leave this hornworm in place as a nursery, and when the eggs hatch, the wasp larvae will eat the hornworm. 



  • Most tomatoes are self pollinating and crossing isn’t likely; separating by 25 feet is sufficient for pure seed, except for the potato-leaf varieties like Brandywine.
  • On a small scale, seeds may be scooped from the fruits and dried on a paper towel; for larger quantities or cleaner seed, fermentation for 1-2 days is recommended.
  • Once dry, tomato seed can be stored at room temperature, and good seed retains viability for 5 years or more.