I just cleaned up my balcony on the weekend and this made me think...
I generally hold the opinion that the planters on the railing of a balcony are to small to be effective. But I might as well use the space!
This year I had a little bit more success with sticking overpriced clay cones attached to PET bottles into them.
The breakdown of the PET because of the UV rays is worrying me but I think glass bottles will not work with the cones.
I used some bark mulch as well.
I guess I will try glass bottles with out the cones next year.
The reason why I think that others have more success with the planters is that I`m lazy as hell and in summer they need to be watered twice a day or the soil will be bone dry.
My theory is that if the soil gets bone dry most of the soil life dies and thus the soil gets worthless for the plants. Even if I manage to rehydrate before the plants take damage they will not thrive after the event.
I've had some booming success with plants in pots and some failures. In big pots I've been using the hugelkulture technique of putting chunks of punky wood under the soil, which helps with modulating moisture. I do think a pot can bounce back from bone dry, it depends on the plants and the makeup of the soil. I've had some happy happy red bell pepper and thyme plants together in very dry conditions.
Dominik, Yes the soil microbes can be adversley affected. But moisture will slowly bring them back to life or repopulate the soil. My containers are 2' deep, 2' wide and 6' long, they get watered every day with 1/2gal/hour emitters. But only for 4-10 minutes - depending on the season. The plants thrive. Remember, lettuce, as an example, can have roots 3-4' wide & deep in a good soil. This is why you really have to watch the nutrition & water in a container to keep them "happy".
I guess then that 1/2' deep, 1/2' wide and 2' long is just to small.
But on the other hand I have seen rain gutters with trees growing in them that looked healthier than my plants!
I guess that one of the other problems is that the rain washes away all the nutrients. 2013 was extremely rainy in spring and soil microbes drowned and got washed away with all the nutrients.
Maybe I will try something completely different next year as I have a lot of geotextile left from my quite successful experiment with water cooler bottles.
Some thing like Sepp Holzer's soil sausage maybe with a internal dripline for irrigation.
This looks like a job for .... legal tender! It says so right in this tiny ad: