Monday, March 17, 2014

Selecting Outcrossing Vegetables

Over time, I have contemplated the difficulty of saving seed from crossbreeding plants. Possessing limited space, the backyard gardener can find it difficult to grow the 100-200 plants required to avoid inbreeding depression in outbreeders such as carrots and corn. Even more difficult for the backyard gardener is the ability to select for specific traits in outbreeders, because backyard gardeners cannot start with 400 plants needed cull the plants down to a population of 200.

Purple carrots can exhibit a wide range of color variation

Carrot tops before selection

Carrot tops compared with the other plants in the garden

With these challenges in mind, it is a wonder that vegetable gardeners can improve on any outcrossing vegetable variety. Having a knowledge of what characteristics can be selected and how to select for these traits will enable gardeners from any climate to select vegetables for the attributes that best suit their needs.

Cutting Carrot tops to keep stecklings from transpiring

Composting all these carrot tops felt a bit like a waste

It can be difficult to breed out the dominant white color

My experience saving carrot seeds started a few years ago when I saved some seed of Purple Dragon in my summer garden. The results were fairly good but I had difficulty selecting for the dark purple color that I wanted in the roots because I didn’t know gardeners could select for color in carrots by making stecklings, as shown in The Organic Seed Grower.

A few of the many purple carrots I pulled from the garden.

Stecklings are carrots (or another root crop) that has the majority of its top cut off (to keep from transpiration) and is prepared in a specific way for either winter storage, selection, or both. The great thing about carrot stecklings is that the gardener can cut the bottom of the carrot off to evaluate color, texture and taste. When returned to the garden, healthy stecklings will keep growing and produce seed.

A large bucket full of purple carrots

Sorting Stecklings for Desireable Traits

Though the color of this individual carrot was good, it contracted CMV


Culled carrots end up on the dinner table with asparagus

Another technique I recently taken advantage of was to cluster my stecklings so that I can select seed from the best plants. Though I am still growing out 200+ carrots, I am only saving seed of the best 50 plants. By doing this, I am maintaining genetic diversity (utilizing the total population of 200 plants) while still selecting the carrots that exhibit the most desirable features (dark purple color). The more traits a gardener selects for, the more unwanted plants he/she will need to remove from the population, so it is a good idea to only select for a few traits each time the gardener saves seeds.

Saving seed from the 50 best plants still maintains genetic diversity.

Best Carrots were planted in the middle with the good seed surrounding them.

I often feel fortunate that my mother-in-law is able to travel abroad and speak so many languages. I owe her a great deal of thanks for finding these purple carrot seeds for me during her travels.

A little tight, but these carrots will still produce seed.

The stecklings begin to sprout.

The point of this post is to emphasize to others that, even with limited space, backyard gardeners can use selection to produce more desirable vegetables – as long as they know how.

Even gardeners with limited space can select great carrots.


  1. Are the purple carrots different in taste or nutritional value from the orange and therefore more desirable? OR are they just different and unique?

    1. Dear Swimray,

      The Purple carrots have a greater level of anthocyanins while the orange has a greater level of beta carotene. The taste is a little different. They are pretty unique.



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