Schwarzwalder could very easily grow in 5" plastic pots on a sunny balcony. They like moderate water c good drainage.
The Taro should be grown separately in a large pot (They get pretty big), as it will need more water once it gets going. Taro likes "wet feet" in the Spring and Summer, whereas Mini Callas like to dry slightly between watering.
In the fall, reduce water, let foliage frost back, and bring in before first freeze. Unearth when dry and remove dead foliage and roots. Sore in dry peat or soil in a cool unheated basement until Spring, when night temps reach 50 degrees F or so.
The Taro may overwinter in the house in a sunny window with a little less water. Keep moist to wet, depending on how much light you can give it. You can also store dormant for a few mos c the Callas by reducing water in Fall, letting it frost (but not freeze) and storing dry. Unearth when completely dry, remove all dead leaves and roots and store in dry peat or soil until night temps reach 65 degrees F or warmer.

Thanks Leafhead. I will do just that. I dont / cant bring Taro inside coz I have a huge pot for it and dont have the place for it indoors. Last year, after the leaves died, I dug it out but it was shrivelled and I threw it away. I always have left over sprouting Taro bulbs that I dont have to bring them in. Love those gorgeous huge green leaves. Cant wait for the mounds of snow in my balcony to melt :D

And Calla... I hope it turns out to be as pretty as in the pictures. Thanks again for info on storing it in winter.

You're more than welcome, and I know EXACTLY what you mean by those mounds of snow!!
Happy Aroiding!!