Experiment with sweet corn, gone wrong or right?

[anothermemory]

After reading a bunch of articles on growing corn in containers I decided to put it to the test. I took three window planters (the 12" deep ones) and filled them with organic soil. I mixed organic compost into one of the containers, a vegetable pellet feed into one, and left the other one straight soil. Of course, they all have had different growth rates. I transplanted them at 3-4 inches tall.

One box has 12" stalks, thin and quite sad looking.
One box has a decent amount of growth at a little over 2" tall, has started silking.
The third box is 4' tall, multiple stalks and silking.

I marked the boxes so I could keep track of their progress, but my markers wore clean from the rain...and now I have no idea what I did right on the third plant. I'm guessing it was the one I left alone, and maybe the compost in the first one burned the roots.

Any ideas? Obviously this is my first time growing sweet corn, otherwise I'd know better than to tinker around with soil.

Also, on the first box with the stunted corn...it is too late to transplant them in clean soil or should I pull them out? They were planted mid-July and I live in Florida, if that's any help. Thanks!

[rainbowgardener]

You can not burn plants with organic compost. You can plant directly into it with no soil mixed in and things will thrive. It's not a good thing to do (use pure compost) in containers, because the compost can be too heavy and dense, but it won't burn. My guess for the ones doing well are the ones with compost added.

It's a toss up about the other two. Depends on what your "regular soil" is like and what is in the "vegetable pellet feed" and what concentration you used.

[jal_ut]

When corn is planted in a field, the roots will go out four feet or more in all directions. Putting corn in a pot sure restricts its root development. I would be surprised to see you get much from container grown corn. Corn is a big plant, it needs room. Room for roots. Room for leaves.

[pharmerphil]

jal_ut is correct, the root system for corn to produce needs to be extensive.
And they will be almost as long as the plant is tall in each direction
I haven't ever heard of raisin corn in containers, well except for starting them in pots for an early start...but even then, they must be planted before they are root bound.
furthermore, corn IS a heavy feeder..requiring alot of nitrogen...

[rootsy]

A corn plant will have a root ball that is 2 - 3 feet in diameter by up to 4 feet deep. With more than 90% of the roots in the first 2 -3 feet of root ball depth.

Crowding, lack of nutrients and lack of moisture will stunt corn... root bound is what I'd figure in those containers...