Variety Spotlight: Top Hat Corn


This variety spotlight on Top Hat corn not only tells the story of the corn, but also the breeder behind the corn, Jonathan Spero. It is our ‘go to’ sweet corn that checks all the boxes for sweetness, productivity, ear size and maturity time. To boot, it was developed just north of us in southern OR. We had the luck to trial four of Jonathan’s corn varieties in 2015 and out of that trial we loved Top Hat. From the looks of it, my farm babies did too! 

Spero’s goal in developing Top Hat was to create an open pollinated (OP) and open sourced modern sweet corn variety. OP and open source varieties are free: free to be used by anyone for anything, free to pollinate naturally, and free from variety patents. In 2014 the Open Source Seed Initiative, OSSI, coalesced around the immediate need to protect seeds from exclusive ownership by corporations or individuals. 

Spero, who also sat on the board of the OSSI at the time, released Top Hat corn with the OSSI pledge: “You have the freedom to use these OSSI-Pledged seeds in any way you choose. In return, you pledge not to restrict others’ use of these seeds or their derivatives by patents or other means, and to include this pledge with any transfer of these seeds or their derivatives.” 

The story of Top Hat begins in 2002 when Jonathan planted a trial of sixteen commercial hybrid varieties of sweet corn to choose the best one as breeding material. He observed Tuxedo to be “the first to germinate and it grew ears with a long husk cover that is some protection from insect damage. It held up well under weed pressure and produced a fairly consistent two ears per plant.” 

Here on our organic seed farm we appreciate those qualities in corn as well. Long husk cover can help keep corn earworm damage to a minimum and after 17 years of farming the same fields we have substantial weed pressure. 

The next year Jonathan planted a large plot of the F1 hybrid Tuxedo and saved seed from the 300 nicest ears. The season after he planted this seed and saved seed, again, from the nicest ears on the nicest plants. 

Then, in the F3 generation he encountered something unexpected. In his words, “Tuxedo is supposed to uniformly possess the sugary enhancer (se) gene, so I did not expect lack of sweetness to be an issue. I found, however, in the F3 generation when I started conducting taste tests, many of them weren’t all that sweet. So began the search for sweetness.” 

To speed up the selection process for sweetness, Jonathan again selected the sweetest ears and then took his selection a step further by actually selecting the sweetest kernels from each ear as well. To do this he harvested the ears about two weeks after they were ripe to eat but not yet dry. He removed the husks and dried the ears standing up to get even airflow all around. 

After a few days many kernels, but not all, had started to shrivel and dry. Greater sugar content causes greater osmotic potential or pressure in the kernel, and these will shrivel and wrinkle more slowly. Using a marker pen, he marked all the kernels that had not yet started to wrinkle. These marked kernels were his F4 planting stock for the following year, and he repeated the process again two more times, saving only the sweetest kernels. 

Today the seed stock we sell was actually grown in 2019 and is the last improved seed crop of Top Hat that Jonathan grew before his untimely passing in the spring of 2020. Though we had corresponded for a couple of years about his corn, I only had the chance to meet him once at the Organic Seed Growers Conference in early 2020. He was humble yet dedicated to his seed work and seemed a gentle, kind man. I know he has been greatly missed in the seed growing community. 

We also carry several of his other corn varieties including Festivity Sweet corn, Zanadoo and Tuxana. We give many thanks to Jonathan for his breeding efforts and plan to keep these excellent varieties commercially available. 


Corn Planting Tips!

Corn loves nice warm soil, so be sure to check your local weather and delay planting if a cold snap is headed your way. There are two methods to planting corn.

1. Direct seed means to plant the seed in your garden bed. Corn needs spacing of 12-18" to grow large and produce 2 ears per plant. If you plant too densely your production per plant will go way down. If you have plenty of seed you can plant every 6 inches and thin the bed after germination. Seeds should germinate within one week with regular water and warmth. You can also soak seeds overnight in water then plant to speed germination.

2. Transplanting corn is possible and it works out really well if you do it right. We do this all the time! Sow corn seed in 1-2 inch cells and transplant to garden when the shoots are 1-3 inches tall and you can see roots trying to come out of the bottom of the cells. If you wait too long the seedlings will be stunted so be sure to get them in at this stage. I usually transplant them along drip tape and space them 12-18".

Corn is a heavy feeder meaning it loves a lot of nitrogen. That makes sense when you see what a massive plant it is! So be sure to enrich your soil with plenty of compost, cover crop or manure prior to planting. I generally find no need to 'feed' my corn during the season if I have already fed my soil.

I love, love, love standing in the middle of the corn patch as the tassles and silks emerge. The honey bees swarm to the tassles to collect pollen and fill the air with their song. Corn will still need plenty of water at this stage and extreme heat and wind can decrease yield. Sowing early maturing varieties in areas with extreme heat can help ensure a good crop.

Corn is usually ready to eat when the silks have browned. You can check for readiness by carefully peeling back the husk and even taking a nibble! Sweet corn has a window of good eating before it will become more starchy so pick it when it tastes good. It can be stored in the fridge for a little while and will stay sweet. If you have a lot ready at once you can parch the ears and cut the kernels off to freeze!

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