1. Size does matter
Corn needs good soil, and lots of it, so you need something large enough to grow it in. The bigger the better, but given this is a balcony you also need to consider weight. The bathtub idea, while romantic when considering the claw footed beauties I'd seen in home magazine pictures of million dollar bathrooms weren't going to cut it here. Not even your standard bath, simply because of the weight. The solution ... polystyrene boxes. And the best thing was they were free! Lots of people grow in these things, and a regular one could fit about 5-6 corn stalks. That wasn't big enough for me, and I found they dried out pretty quickly so I put two and two together, and when I say that I mean I put two polystyrne boxes together (with their middles cut out) and made myself a megapot. Now this held even more corn and gave it enough nutrients to survive.
This is megapot above, when filled with this winter season's crops -broccoli, kale, lettuce and carrots.
2. Potting Mix
Same as I say for tomatoes, and for any vegetables, use the best potting mix you can afford/make. Corn seems to like to be fed, so do it.
3. Hand pollinate
Not with a toothbrush like you do tomatoes, (wierded out by that statement, then visit this blog post to get an understanding) but with the wind. The pollen from the tassels or corn flower (the bit that comes out of the top and has flowering sorts of things on it) needs to rendezvous with the silks (the lady bits) on the top of the little itty bitty corn (and yes the corn inside there pretty much is baby corn, give or take a few days.) Still confused, see below, the bits in exhibit A (left, flowers/tassels) need to meet the bits of exhibit B (right, silks).
You need to do two things to help this along, and one is not to play Barry White on the balcony and leave glasses of wine lying around to set the mood. What you do need to do is to plant the corn in clumps so it has buddies nearby (another reason why megapot is the best) and then shake it a little when the flowers and silks are visible. Sometimes the tassels/flowers appear a lot earlier than the silks, just hang tight, and usually things work out. If not (which has happened) it could be because the temperatures are wrong for corn and unfortunately there isn't much you can do short of hoping someone else has a corn crop on the balcony next to you.
Each silk that is pollinated is a kernel so you want to make sure you get that pollen where it is needed. If not you might end up with a sad looking corn like this:
or worse, you might end up with no corn at all. (the pot pictured well below with the 3 sisters technique is an example of weather causing odd growth, it sometimes happens, and you just have to go with it.)
4. When do I pick it?
Once they're pollinated they'll grow and fill out. You will see this happened over the next week or two until they look pretty big and juicy. The silks will brown off and you may even see kernels sticking out the top of it. That's when you know they are ripe. They'll also stick out at a greater angle than before, even up to 90 degrees, (see maths does come in handy in real life, thanks Mrs Fleet and Mr Kennelly for giving me the mathemetastical grounding to work out the ripeness of corn!) The corn below is almost right, it is starting to move away from the stalkm but needs to get a little fatter.
Once ripe just rip it off the stalk, or twist if you feel like being delicate. You can eat it without cooking if it is this fresh. It is great in salads or just as is. If it is a little old or mealy then cook it, just remember to remove the husk before serving.
5. Other little tidbits.
Try the 3 sisters technique ina really large pot (I did.) It is corn and beans and squash/pumpkin. In the first three sisters pot the corn went really well, the beans were tasty but the pumpkin died. I might try this experiment again next summer. Below is the only picture I have of of the second 3 sisters pot. The corn in this pot struggled as the weather was too hot and it got too straggly. I got a few ears of corn from this one, but not many. However, in this case, at least the zucchini thrived.
Also, corn isn't just yellow. I grew the most amazing yellow and white version last season and there are also fully white versions.
If you want to go exotic you could grow other kinds of corn, red, black, blue, multicoloured. These versions aren't sweet and are often used dried, popped, ground or decoratively. Still they can look amazing and I am sure you could have all kinds of kitchen fun with these veggies. If anything this post proves that with the right knowledge and plannig you can grow just about anything on a balcony! Ever grown corn? Got any more suggestions?