Watering plants on a condo balcony can be a pain because you can’t rely on the rain to give you a break unless you have an uncovered balcony.
And you can’t run a hose outside so you need to carry water back and forth… I’ve been considering making a hose that could connect to my kitchen faucet so I could run water directly outside…if anyone’s tried this I’d love to hear your thoughts.
In the meantime, whenever I have time I fill Perrier bottles with water and turn them upside down into the soil.
It’s best to water the plants first then do this otherwise all the water in the bottle will likely empty into the pot. For the science of this you can watch the water globe infomercial?
I’ve read that potted plants should almost be watered daily!
I’ve found this method usually gives me about 5 days grace. And it delivers water to the roots without wetting the leaves which is better for the plants. Plus there’s less water dripping down onto my neighbors balconies from over watering.
If you want to fertilize at the same time you can use worm tea instead of water. I like to make the worm tea right in the bottles.
Either put about 1 tsp of compost in each bottle (my bottles are 750mL so adjust to the size of your bottle but it doesn’t need to be too exact) and fill with water or but the compost in a watering pot and add to bottles. In both cases a funnel is helpful. Let the tea sit in the bottles overnight before turning them into pots.
This allows me to make and store worm tea in batches without getting too many things covered in compost.
You could also dissolve another fertilizer into the water, just remember to read the packaging carefully for frequency and ratios so as not to over fertilize your plants.