>>1565407>Also is it absolutely necessary to plant them in pots that have drainage holes at the bottom?Not necessarily. Self-wicking pots and gravity fed sub-irrigation methods do have an emergency drainage hole but not at the bottom. It is supposedly used to ensure the plant does not drown on rainy days but also to ensure you do not drown it by over-watering while the root system is forming.
The pic is my ginger plants on a gravity fed sub-irrigation system. You can see the drainage hole (with a tube) 7cm from the bottom. It hasn't leaked any water since I properly adjusted the irrigation valve.
