Corn cross polination

I have five acres. I planted Johnny Red at one end of the property and Hickory King at the other. Should cross pollination be an issue?

Hi Don,
I am not a corn pollination expert, but I believe five acres apart should be enough. A five acre plot, however, could have parts that are more narrow. How big is each planting? (Did you plant a small garden size or plant a whole acre?) If there are trees and things in between, you might be able to get away with less. The Internet seems to say somewhere between 250ft and a mile is the distance. So real specific :)

The plots are relatively small, 40X60. I've got squash and beans in with them. There's not a tree on the place. I should plant a shrub or something, I suppose.

I have planted three types of corn only 15' apart- a sweet corn, popcorn, and flour corn. My property doesn't get much wind, especially in summer, and I've always had to hand pollinate my corn to get better results so I figured it wouldn't cross pollinate much and it didn't!

I even had success growing the saved seeds of the flour corn the next year. There was the odd kernel on the occasional ear here and there but the vast majority of it was perfect.

So I would say it really depends on wind. Also I wouldn't do it if I were planning on selling seed but only for my own purposes.

Here's a picture of how close I was able to plant my corn.

As long as Johnny Red and Hickory King aren't too close in proximity, it shouldn't be a problem. Cross pollination can get a bit tricky, but with your five acre buffer, it looks like you're doing all the right things!

The corn cross pollinates very easy that close. The trick is to plant different varieties a couple weeks apart and pay close attention to the time each variety will naturally mature. That way when the variety is tasselling wind borne pollen none of the other varieties are receptive yet. They can be grown right next to eachother if you time your planting  that way.

Mark Wyborny wrote:The corn cross pollinates very easy that close. The trick is to plant different varieties a couple weeks apart and pay close attention to the time each variety will naturally mature. That way when the variety is tasselling wind borne pollen none of the other varieties are receptive yet. They can be grown right next to eachother if you time your planting  that way.

Agree. I can easily find cross pollinated seeds 60 feet apart. I walked 11 rows into the neighbor's field and found a few colored seeds from my corn.
I planted commercial seeds of specific varieties and found evidence that the grower did not sufficiently isolate his plots.

Thom Bri wrote:

Mark Wyborny wrote:The corn cross pollinates very easy that close. The trick is to plant different varieties a couple weeks apart and pay close attention to the time each variety will naturally mature. That way when the variety is tasselling wind borne pollen none of the other varieties are receptive yet. They can be grown right next to eachother if you time your planting  that way.

Agree. I can easily find cross pollinated seeds 60 feet apart. I walked 11 rows into the neighbor's field and found a few colored seeds from my corn.
I planted commercial seeds of specific varieties and found evidence that the grower did not sufficiently isolate his plots.

I guess that just confirms that I get close to zero wind over the summer. I plant purple popcorn, a yellow sweet corn, and a rainbow field corn with blue, orange and red. So the colors, texture, flavor, and size are all very different. I can plant them close, with ten feet beds between them planted with other plants and I might find five wonky kernels out of hundreds of cobs. I save my own seed and replant and it comes true. They tassel at slightly different times with a little overlap so I'm sure that helps too.

The timing thing is underrated. Two varieties maturing at wildly different rates can end up fine grown right next to each other, while two that mature at the same time would cross even at distance. Worth checking the days-to-maturity on both just to know where you stand.

I agree on the time window issue. I work hard to get my broad grex to hybridize and I think next year I'm going to plant one row each week to help get things to mix up in ways they can't normally.

Joao Winckler wrote:The timing thing is underrated. Two varieties maturing at wildly different rates can end up fine grown right next to each other, while two that mature at the same time would cross even at distance. Worth checking the days-to-maturity on both just to know where you stand.

I planted a row of a different corn in the middle of my usual corn this year, hoping for some cross pollination. Turns out the new corn pollinated a MONTH later than my usual corn. Oh well.

Thom Bri wrote:

Joao Winckler wrote:The timing thing is underrated. Two varieties maturing at wildly different rates can end up fine grown right next to each other, while two that mature at the same time would cross even at distance. Worth checking the days-to-maturity on both just to know where you stand.

I planted a row of a different corn in the middle of my usual corn this year, hoping for some cross pollination. Turns out the new corn pollinated a MONTH later than my usual corn. Oh well.

You can save your good pollen you want by shaking tassels into a jar. Add a dessicant package from a new pair of shoes you bought or something to help keep it dryer until next season and put the jar labled in freezer. Next season pollinate the  receiving silks with that and a paint brush on a few dry mornings after cutting off the tassel of the receiving corn variety before its tassels open, plus clamp or tape a loose plastic bag over its silks . Pollen dies when it gets wet. That will ensure it works at least next time. I havent done that myself but shown how by others. I am sure you just needed reminding of that insured method for next year.

Mark Wyborny wrote:

Thom Bri wrote:

Joao Winckler wrote:The timing thing is underrated. Two varieties maturing at wildly different rates can end up fine grown right next to each other, while two that mature at the same time would cross even at distance. Worth checking the days-to-maturity on both just to know where you stand.

I planted a row of a different corn in the middle of my usual corn this year, hoping for some cross pollination. Turns out the new corn pollinated a MONTH later than my usual corn. Oh well.

You can save your good pollen you want by shaking tassels into a jar. Add a dessicant package from a new pair of shoes you bought or something to help keep it dryer until next season and put the jar labled in freezer. Next season pollinate the  receiving silks with that and a paint brush on a few dry mornings after cutting off the tassel of the receiving corn variety before its tassels open, plus clamp or tape a loose plastic bag over its silks . Pollen dies when it gets wet. That will ensure it works at least next time. I havent done that myself but shown how by others. I am sure you just needed reminding of that insured method for next year.

I have considered it and pretty much decided no. My corn already has a long pollination period, due to past mixing, and adding some very outside-of-average mix will only make it worse. Push it too far and you end up with poor overall pollination.

I am a corn amateur but here is something I am thinking about regarding timing and cross pollination. I have been working with MN 13 heirloom corn since 2012 or thereabout. I plant no earlier than June 1 (this year June 5) when most of the area conventional corn is planted by May 15. The MN 13 I have is thought to be an 87-day corn, most of the local conventional corn is likely 90 days. Would the same corn, some planted on May 15 and some planted on June 1 have about the same number of days to pollination? How does daylength come into play? How about the maturity difference, more days than the planting differential, again with daylength in mind.

Doug McEvers wrote:I am a corn amateur but here is something I am thinking about regarding timing and cross pollination. I have been working with MN 13 heirloom corn since 2012 or thereabout. I plant no earlier than June 1 (this year June 5) when most of the area conventional corn is planted by May 15. The MN 13 I have is thought to be an 87-day corn, most of the local conventional corn is likely 90 days. Would the same corn, some planted on May 15 and some planted on June 1 have about the same number of days to pollination? How does daylength come into play? How about the maturity difference, more days than the planting differential, again with daylength in mind.

Simple answer. Yes, about the same number of days.
You get consistently increasing day length for both planting dates. But northern corn is pretty day-length tolerant so I don't worry about that unless I am planting a tropical variety.
Some variables:
Slower germination for early-planted seed if the ground is cold.
An early dry period will also slow the plant down.

This last year was a perfect example. I planted in May and then had an entire month of drought. The sweet corn I planted first only sprouted a little before that which was planted last. So I didn't get the long, slow, sweet corn season I had planned on. It all eventually grew, but...the early corn got delayed.
Then, the Canadian forest fires played heck with everything. It was so dim for weeks on end, I was surprised the corn grew as well as it did. A lot of my veggies hardly produced at all.