Food on the balcony

Our 'yard' consists of the 6x10 ft balcony. We tend to avoid spending time out there, as our downstairs neighbors enjoy using their patio to smoke while discussing personal matters, personal enough they are not worth repeating, with each other or with the person on the other end of the phone. Thankfully our sliding glass door offers enough of a sound barrier that we can almost not hear what they say about 3% of the time. This is not a complaint, but that's how it is.

However, I wanted to make the space useful anyway, so we planted a little container garden. It has beans, garlic, peas, basil, lettuce, spinach, and the newest edition, a cherry tomato.

Growing food naturally and self-reliance have become more and more interesting to me in the last few years, so I checked out a book by R. J. Ruppenthal called Fresh Food from Small Spaces: The Square-Inch Gardener's Guide to Year-Round Growing, Fermenting, and Sprouting. If the title isn't too long for you, the book actually has a lot of cool hints on growing stuff with what you have. He says that you can probably grow 10% of your own food, even in an apartment or cold weather climate, if you know how.

These are the most helpful things I've learned so far:

• Avoid over-watering. That is the way most people kill container plants. It prevents the roots from getting oxygen and allows for root rot. This is probably how I killed the first round of planting.
• Avoid over-fertilizing. This is number 2 killer. Also, use natural, slow release fertilizer to get the most nutrient rich food (i.e. food like it's suppose to be).
• Even if the amount of sun you get is limited, plants can still grow, if you reflect light and move your pots around to follow the sun, if possible. Too bad we can't all have one of these: http://greenupgrader.com/files/2008/10/image1.gif

I have noticed that some of the plants will start to dry up right where it meets the dirt, like someone who squeezes the toothpaste tube in the middle. The picture shows two healthy plants on the left and one that is starting to rot on the right. The roots look fine, and so do the leaves for a while, until the whole thing dries out. Any ideas on what causes that?