Because corn relies on wind to carry pollen from the tassels to the silks, the light pollen grains may travel a few miles before finding and pollinating a silk. Your neighbor’s corn can therefore very easily pollinate yours, making it tricky to save pure seed from your open-pollinated corn.

During the 2013 growing season at Heritage Farm, the Preservation garden crew grew out 18 varieties of open-pollinated corn from our seed vault to replenish the supply in our collection, increase the viability of the seed, and evaluate varietal characteristics.

Preventing cross-pollination between these varieties can be difficult, especially considering that Heritage Farm is located in Northeast Iowa, a region known to farm almost exclusively genetically modified (GMO) feed corn and soybeans. Cross pollination with GMO corn is of particular concern for preserving historic varieties because GMO corn contains genes not historically found in the corn genome.

Preventing Cross-Pollination

There are a few ways to prevent cross-pollination among corn varieties, the most basic of which is to grow only one variety each year. But if you have an appetite for diversity, there are options. One method involves utilizing timing and can be done by simply growing two varieties that vary dramatically in days-to-maturity. For example, a 100-110 day corn variety such as Bloody Butcher can be grown next to a 70-80 day corn such as Blue Jade. This method is risky, though, and also does not account for what your neighbor is growing.