Let's Talk About Corn!
I recently saw a question about corn on a mailing list, and wrote up a detailed answer, which I wanted to share with you, my faithful and oh-so-patient readers. If anyone still checks this blog for updates, that is-- mea culpa!!
Someone wanted to know if they could plant sweet corn and flour corn together, or how far apart they would have to plant it. They wanted to grow flour corn to make tortillas.
What Kind of Corn for Tortillas?
There are several types of heirloom corns: sweet corn, flour corn, flint corn, dent corn, pop corn, and parching corn. One variety may combine several of the characteristics. Apparently field corn, also known as dent corn, is the preferred variety for tortillas.
By the way, to make masa dough for tortillas, dried dent corn must go through a process called nixtamalization, involving lye, before being ground into masa.
Can I Mix Sweet Corn and Non-Sweet Corn?
Here is how corn works-- there are as many silk strands at the tip of an ear of corn as there will be kernels on the ear!
Each tassel of corn silk draws a pollen grain down it to pollinate one corn kernel on the ear. So each kernel on the ear of corn can potentially have a different variety as a parent!
Modern sweet corn (SU1 gene) grown can be grown near non-sweet corn, but the "supersweet" varieties (SH2 gene, usually marked SE for Sugar Enhanced) should not be grown closer than 250 feet from other types (including sweet). (info via UC Davis article ) The supersweet corn silk can pick up other corn pollen, which is generally dominant over the supersweet corn genes, and thus portions of the ear may pick up kernels that are not sweet, and/or have different ripening characteristics.
There was a UC Master Gardener Santa Clara corn trial in 2007 for sweet (SU1) varieties which suggested that Silver Queen or Peaches & Cream would be good choices. These should be able to be grown with or near non-sweet corn.
If you wish to plant super-sweet corn, a UC Davis article for small farmers mentions "Kandy Korn" as a super-sweet variety that needs no isolation from other types. Kandy Korn seeds appear to be available from Territorial Seeds, Gurney's, and Henry Field's.
Can I Get Sweet Corn and Tortilla Corn from the Same Plant?
Yes! Corn has been domesticated for a very long time, and many of the folks doing that also loved some nice young sweet corn, steamed in the husks or roasted! There are some multi-purpose corns that can be eaten young as sweet corn and also left to mature for dent corn.
"Green corn is harvested when the corn is still in the "milk" stage, when the kernels are at their sweetest and can be eaten fresh. Varieties that are sweet when young are Blue Clarage, Bloody Butcher, and Black Mexican/Iroquois."ATTRA.org article
So you could theoretically plant all dent corn of one of the above varieties and still have sweet corn to eat, by harvesting some of the ears early. Some great info on corn varieties can be found in an appendix to ATTRA's wonderful article on companion planting.
Seed Savers Exchange online is a good place to find heirloom corn varieties, as is Victory Seeds, and Native Seeds Search.
Happy planting! Get some corn going this year!