Wednesday, January 28, 2009

The ‘birds and bees’ of saving seeds

Will saving seed from last year’s favorite vegetable pay off?

I don’t save seeds of F1 (first generation) hybrids because they lose hybrid vigor, don’t come true to type and most are patented anyway. Tomatoes, peppers and eggplants are ninety plus percent self pollinated and will come true to type if they are not a hybrid.

I save seeds of a favorite lettuce with success. Herbs such as dill self seed or can be collected and sown in either fall or spring.

What does and doesn’t work in terms of “the birds and bees” of the garden? Cucumbers do not cross with pumpkins, squash or melons but readily cross with each other.

Varieties of summer squash will cross with one another and with pumpkin. They don’t cross with winter squash. Cantaloupes do not cross with cucumbers, watermelons, pumpkins or squashes. Winter (fall) squash doesn’t cross with melons, pumpkins or summer squash. Sweet corn crosses with itself and also with field corn.

Potatoes by the way don’t cross with tomatoes. When potatoes produce fruit on the plants those aren’t a tomato, just a potato fruit. Propagate potatoes by saving and cutting tubers into seed pieces with an eye (sprout), not from potato fruit.

Many people prefer to buy seed and it generally is one of the least expensive investments in the garden.

I get a question every year from a Colorado gardener who claims they purchased seed and the plant produced a garden fruit monstrosity. Maybe a mix up occurred at the seed producer or more likely the seed of a hybid variety reverted to parental characteristics from last year's fruit dropped in the garden.

“Weird” crosses won’t show up in the year they are made. Crossed plant genetics are stored in the seed and don’t affect the fruit characteristics the year of the cross. The exception is sweet corn where crossing can affect the taste of the kernels that same year.

Certain crosses are genetically impossible because chromosome numbers aren’t the same, won’t successfully match up and can’t produce viable seed. See chromosome numbers below.

Vegetable chromosome counts
Like chromosome numbers need to be present to even think that crossing is possible (pumpkin and summer squash). Genetically distant and totally unlike plants won’t cross even if numbers happen to be the same (cantaloupe and tomato).

  • Cantaloupe 24
  • Cucumber 14
  • Potato 48
  • Pumpkin 40
  • Summer squash 40
  • Sweet corn 20
  • Tomato 24
  • Watermelon 22
  • Winter squash 24

[Pumpkin photo credit Carl Wilson]


  1. I was under the impression that you can plant the seeds inside the potato fruit.


    1. The cherry tomato-like fruits are formed from pollinated flowers and bear potato seeds. The fruits aren't edible and the seeds will not grow true to type, so there's no reason to save them. Luther Burbank's famous Russet potato variety grew from seed he saved, but there's little chance of duplicating his good fortune. Some potatoes such as Yukon Gold bear fruit more often than other potato varieties.