There are several myths surrounding cross pollination in the vegetable garden. This post will help clear up those misconceptions.
I’m writing this post to clear up a common misconception about cross pollination in the vegetable garden. Over the last year alone I can think of at least 4 or 5 times where I have seen long discussion threads about cross pollination in the squash family. Even on the Stoney Acres Facebook page.
It usually goes something like this: “My acorn squash turned out all stringy like spaghetti squash this year. I think I must have planted them too close together and they cross pollinated”. This comment is then followed by a long discussion about how the same thing happened to me only it was cucumber and cantaloupe. Or “I fixed that problem by planting them on opposite sides of the garden”.
NO, MY FRIENDS!! THAT’S NOT HOW IT WORKS!!!!
Let’s talk about the science behind cross-pollination.
What is cross pollination?
Cross pollination is when the pollen from one plant is transported either by wind or insects to the flower of another plant. The genes from the two plants then combine to create a seed with genetic characteristics of both parents.
Cross pollination only occurs between members of the same botanical species.
The most prevalent pollination myth you hear about is in the botanical genus classification Cucurbita. Cucurbita includes many different varieties. Squash, Cucumbers, and Melons. But each of those 3 is just a botanical grouping and remember cross pollination can only occur between members of the same species. So Cucumbers CAN’T cross with squash and melons, Melon’s can’t cross with squash, etc.
But then it gets even more complicated. So remember cross pollination only occurs between members of the same botanical species. So even within the melon “family” you have limited cross pollination. For example, Watermelons and Cantaloupe are members of different botanical species and CANNOT cross.
But within botanical species, you can have cross pollination. So for example, Zucchini, Pumpkin, Acorn, and Spaghetti squash are all members of the same species (Cucurbita pepo). So all of these can cross with each other and produce seed that is a genetic combination of the two parents.
Cross Pollination does not mean funky fruit this year
Here’s where the common misconception or myth comes in. Cross pollination only affects the seeds, NOT THE FRUIT, this year.
So if a pumpkin and a zucchini cross pollinate the pumpkins and zucchini that you get this year will be perfectly fine, they will look right and taste right. That is because the type of fruit a plant produces this season is determined by the seed it was planted from, not the seed it will produce. So if a pumpkin and a zucchini cross you will have a Pumpcchini NEXT YEAR, when you plant the seed that was a result of the cross pollination. The combined genetic material is in the SEED, not the fruit.
Another common myth is if you plant sweet peppers and hot peppers together they will cross and all your peppers will be off. Again this is a myth. Yes, hot and sweet peppers are members of the same species, but the cross pollination affects the seeds, not the fruit!
So what does this mean for you? If you have funny shaped, funny tasting or funny colored fruit this year it is caused by one of two things:
- You planted a “bad seed”. If you are getting your seed from a reliable commercial source this is very unlikely. Commercial producers go to great pains to be sure there is no cross pollination in their seeds, but it does happen every once in a great while.
- Something else is wrong. If you have funny shaped, colored or tasting fruit the more likely culprit is some environmental problem. Look at what the weather has been like this season, was it extra hot or extra cool? Has the plant been damaged by pests or other means? Damage causes stress which causes funky fruit. What about herbicide? Is it possible you or your neighbor sprayed too close to the plant and the spray drifted? What is your soil like? You might want to get a soil test to see if your soil needs to be amended to replace missing minerals.
The point is, strange fruit is never caused by pollination issues in the current growing season. That is just not genetically possible!!
One Exception – Corn
There is one exception to this rule. And that is sweet corn. Crossing between sweet corn and either field or popcorn will ruin the sweet corn in the current season. But think about it, what part of the plant are we eating when we eat corn? The seed! So that is understandable. If you would like to learn more about how to deal with cross pollination in corn you can read this post I wrote on the topic last year.
I don’t want you to take my word alone for it on this topic, so below are links to a few articles I found on the topic of cross pollination, most of which are form agricultural university websites.