Corn planting time!

Last year's young sweet corn plants with a fiber banana plant to the right. Credit Bridget Aleshire

Last year’s young sweet corn plants with a fiber banana plant and a sunflower to the left.
Credit Bridget Aleshire

A week ago, I showed a group of local Master Gardeners around our gardens. At that point, the raised bed area was a mixed portrait of rowcover and weeds! All the crops were sheltered under cover and all the visible beds were full of weeds. So much has changed in a week. We mowed all the weedy beds, tilled many of them, and removed the rowcover to our strawberry beds and our new cabbage and broccoli planting. We’ve even found time to hoe the planted beds and weed and thin the three beds of beets.

We had more struggles with our broccoli.  A couple of weeks ago, I told you all about the moles gathering nesting material from our first broccoli flats. We dealt with that, planted out what we had left, and moved our second planting to the coldframe. Something browsed on them. Deer? Rabbits? Groundhogs? We sprayed the plants with a stinky deer repellant and scattered hot pepper on them. And covered them at night. Now we’ve planted those out and put the third planting in the cold frame. So far, so good. . .

The black center of this strawberry flower show that it was hit by frost and no berry will develop. Credit Kathryn Simmons

The black center of this strawberry flower show that it was hit by frost and no berry will develop.
Credit Kathryn Simmons

We’ve had a couple of cold nights (hence the need to move the rowcover to the strawberries to protect the blossoms from possible frosts.)

Healthy unfrosted strawberry flower. Credit Kathryn Simmons

Healthy unfrosted strawberry flower.
Credit Kathryn Simmons

But overall the season is warming up. After lots of waiting we are finally getting asparagus. Many of the signs of spring all happened in rapid succession: the lilac is blooming, morning glories and smartweed have germinated, the crimson clover cover crop is starting to flower and I’ve heard the whippoorwills at night.

Crimson clover is a beautiful and useful cover crop. Credit Kathryn Simmons

Crimson clover is a beautiful and useful cover crop.
Credit Kathryn Simmons

The white oak leaves have definitely exceeded the size of squirrels’ ears. This is our sign to sow sweet corn. We did that yesterday. Bodacious, 77-days to maturity, yellow, great flavor for corn this early. These days we hedge our bets and also extend the harvest period by sowing the second half of the patch 3 days after the first half. Contrary to myths you might have heard, it is quite possible to transplant sweet corn, so those in marginal climates don’t need to give up hope. We usually prepare some plugs the same day we sow our first corn outdoors and use these to fill gaps at the first cultivation.  If disaster doesn’t strike and there are no gaps worth worrying about, we give the transplants away to local gardeners who were less lucky, or didn’t get round to direct sowing their own.

We use 200-cell Styrofoam Speedling flats (1″, 2.5 cm cells) with one corn kernel in each cell. We float them in a tank of water until we set them out. Some vegetable seedlings would drown if continuously in water, but corn does not. It is important to transplant the corn before the plant gets too big and the taproot takes off. Two- to three-inch (5–7.5-cm) plants seem OK. The plugs transplant easily using butter knives.

Corn has no tolerance to frost. However, escape from a late spring frost is possible if the
seedlings are less than two weeks old and not yet very tall, as the growing point may still be underground.Thus, in a spring that promises to be warm and dry, it is possible to risk an early planting as much as 2–3 weeks before the last frost date. Having some transplant plugs for a backup helps reduce the risk level.

Here’s an aspect of hybrid corn varieties that confuses many people: There are several genotypes, and if you inadvertently plant a mixture of different types, it can lead to starchy unpleasant-flavored corn. Ignore those cryptic catalog notes at your peril! here’s the Cliff Notes:

Normal sugary (su or ns) types have old-fashioned corn flavor but are sweeter than open pollinated varieties, although the sweetness disappears fairly rapidly after harvest. Not a problem for home gardeners who can cook the corn they harvested earlier that day. Most can germinate well in cool soil. 

Sugary-enhanced (se) and sugary enhanced homozygous (se+ or se-se) types are more tender than (su), and slower to become starchy after harvest. Most, especially the (se+) types, are sweeter than (su) types. We grow (se) and (su) types, and avoid the others – sweetness and simplicity!

Nearly all newer sweet corn types rely on one of two recessive genes, su or sh2. Cross-pollination with other corn groups will produce the dominant genetics of field corn, that is, starch not sugar. Don’t mix Super Sweet sh2 types with any other corn. Also don’t plant Indian corn, popcorn or any kind of flint or dent corn within  600′ (180 m) of your sweet corn. For this reason we grow only sweet corn in our garden. In case you are tempted by variety descriptions of the newer types, though, here’s more about them:

The Super Sweet (sh2) varieties, also known as shrunken, are very sweet and slow to become starchy. They have very poor cold soil germination. The kernels are smaller than other corns, giving this type its name.

Synergistic (se-se-se-sh2) types are combinations of genetics from several genotypes. Each ear has 75 percent (se) kernels and 25 percent (sh2) kernels. They are flavorful, tender and sweet, but only when they are ripe. If picked too soon, they are a watery disappointment. 

“Augmented shrunken” types contain the sh2 gene and some of the tenderness from the se types. 

We’re looking forward to plenty of sweet corn this year – we’re off to a good start!

One thought on “Corn planting time!

  1. I am getting ready to till this week for the corn so I can plant by next week.if the weather warms up.

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