It’s been a very long time indeed since we have had Sweet Corn in your boxes the 2nd week of June.
Growing sweet corn is more complicated than most people understand. Corn may be one of the most human-altered plants on Planet Earth. It is grown all over the world, on every continent other than Anarctica, for hundreds of different uses. Most of the corn grown in the world is not eaten by humans at all, but rather either fed to animals (feed or silage corn) or turned into ethanol. This is generally known as “commodity corn” and is harvested completely dry. When it is immature and green, commodity corn looks a bit like Sweet Corn. But you tried to eat an ear of it, for example, you would likely find it highly unpalatable: starchy and tough even before it is dried.
Of the corn that humans do consume, most is used for grain (corn meal, polenta, grits, hominy, etc) or canned, frozen or otherwise processed foods. For each of these uses, there are dozens or more varieties that are adapted for specific regions, uses, and other traits. Sweet Corn is considered a fresh vegetable by the USDA rather than a grain, and the seed varieties used to grow it are entirely different from those used for other purposes. In particular, it is more tender and much sweeter/less starchy than “Corn”. And it has been bred over time to stay sweet after harvest.
Plant breeders have developed several different patented methods, each with its own abbreviation, to breed Sweet Corn that will stay tender and sweet for several days. The seed varieties developed using different method are incompatable with each other — cross pollination between them results in unmarketably tough and starchy corn. (Sweet corn is also ruined if pollinated by commodity corn). So a sweet corn grower must choose which type of Sweet Corn they want to grow. To make matters even more complicated, the grower must also choose between white corn, bi-color corn, and yellow corn. All told there are hundreds of varieties to choose from. But planting more than one color type in any given field will result in the kernels being mixed colors.
For at least ten years now, we have been exclusively growing bi-color corn varieties of one “abbreviation” of Sweet Corn because the Northern California market tends to prefer it (in the Midwest, everyone grows Yellow sweet corn while back East, Sweet Corn is mostly white). But we have struggled to find a variety that does well when planted in early Spring and matures in early June. The weather during this time of year is perfect for maturing Sweet Corn, actually better than later in the summer when the extreme heat can cause pollination problems.
The problem is that corn seed needs the soil to reach a certain temperature before it will sprout. Conventional farmers coat their seeds in fungicides that keep the seed from rotting in the soil until this happens, but organic farmers don’t have this option: we have to wait for the soil to warm up before planting the seed. Generally speaking, the earliest we can do this is in mid-March; some years it’s too cold and wet to plant until almost April 1st. Since the varieties of Sweet Corn we have been growing need at least 78 days to mature, the earliest harvest we’ve had is generally around June 20th. There are yellow Sweet Corns that grow more quickly, but until recent no bi-color varieties.
This year, we found a new Sweet Corn variety that is compatible with our other varieties that claimed to mature an entire week earlier. I was a bit dubious but gave it a try nonetheless. We got a nice window of warm, dry weather in mid-March to plant it, but even so I was astonished at how fast it sprouted and how quickly it grew compared to the other varieties. Then, my astonishment turned into alarm as it started tasseling — sending up flowers — when it was only 3 feet tall. Most sweet corn is at least 5 feet high when it does this. I visualized the ears only growing as big as canned baby corn.
Lo and behold, over this past weekend, our new dwarf corn variety began to ripen into respectable-sized ears. Not huge, but not tiny either, they have juicy, tender and sweet kernels that taste almost as good as our main-season variety. And the smaller plants make harvesting easier. But the best thing about the new corn is how much earlier we are able to get it into your CSA boxes.
Our Sweet Corn season will continue through July, then we’ll have a break until Fall when the second, shorter season starts. Enjoy!