Cross Pollination Facts

(Updated: June 25, 2021, 9:21 a.m.)

Through the years, on several occasions I have been asked questions like the following: “How far apart should I plant my pumpkins from my squash so that my pumpkins don’t get messed up?” This question arises from a misconception that cross pollination of “like” crops will harm the quality of the harvested fruit of the crops being grown near one another. The truth is that cross pollination within like crops is not an issue unless you plan to save the seed for next season’s planting. Cross pollination has no effect on the quality of the harvestable fruit. For example, let us say you are growing straight-necked and crook-necked summer squash in the same garden. If they cross pollinated one another, you are still going to get straight-necked fruit on your straight-necked plants and crook-necked fruit on your crook-necked plants, but if you save the seed from any of this fruit and planted it next season, you are most likely going to get mixed results.

So, if you are only concerned about the quality of this season’s harvest, then spacing is not an issue; however, if you are saving your seed, spacing is an issue and the spacing requirements vary between crops. However, there is one crop where spacing is an issue on the quality of the harvestable crop and that is sweet corn. The quality of your sweet corn harvest is affected if it crosses with other varieties and types of corn. For example, if field corn crosses with your sweet corn, then the sweet corn you harvest is going to be tougher and less sweet than you would expect. Even crosses with other sweet corn varieties will influence the quality of your harvest. If you are growing more than one variety of sweet corn, it will be necessary to maintain a distance of at least 400 yards to prevent cross pollination. This is not possible for most home gardeners. Another method of preventing cross pollination is staggering the plantings of these varieties so they are not blooming at the same time.

For more information about the pollination and cross pollination of vegetable crops, please visit the following links:

Pollination of Vegetable Crops

and

Pollination Basics - June 2019