Most people don't consider the balcony a suitable place to have a garden.  In fact a large percentage of apartment balconies are used for nothing more than storage and worse, nothing.  Urban Gardener suggests you get a little more out of your space, here are some great balcony gardening ideas.

1. cherry tomato plants
   • all you need are a couple old flower pots or even buckets.  Depending on how nice you want things to look out there.  If cost is a factor, just get 4L ice cream pail, fill it with soil to about the top, put an old t-shirt over the top of the buck so the neck of the shirt is at the top and the sleeves hang off the side and plant the cherry tomato plant in the middle.  Voila.  In no time it will be sprouting and fruiting.
2. beans
   • beans love to climb and landlords hate when they climb their walls.  All you need to grow beans and NOT get into trouble is to start them in a long railing style planter box.  This planter should be about 10cm wide and about 60-100cm long and about 10cm deep.  Fill that with soil to about 2 or 3 cm from the top.  If you have a wall along one site of your balcony put the planter in front of that and start your beans.  As they grow they will need "stringers" to grow up - these just need ot be strings attached to the back of the planter box.  These strings can attach to nails near the roof or to a bookshelf in behind.  If you have nothing to attach them to, you can get a lattice board that fits the width and height dimensions of your balcony. 
3. chinese snow peas
   • follow the same instructions as above, just use snow pea seeds.
4. rocket
   • this is a GREAT green addition to pizza, salads and sandwiches.  It is one of my favorite greens.  Rocket grows really well in a pot.  Plant it thinly into a good organic soil.  The planter can be a nice long planter box like the suggestion for the beans and peas.  It could stand to be longer and wider.  I put this in front of my balcony door (the one that doesn't slide) and it runs to the wall. 
5. peppers
   • be careful when you choose your seeds or these will end up being just decoration... jabaneros are way tooo much for some people...  These will grow just like your cherry tomatoes.  Follow the same instructions there.

A balcony garden does more than just help you beautify your space.  It provides privacy and wind protection as well.  A great natural balcony fenc is feather reed grass.  This is an ornamental grass the blooms in early summer.  This is a great background to a garden or natural wall in front of a railed balcony.