Colocasia Fontanesii is another cold hardy tropical plant from Southeast Asia. It has large dark green, glossy, waxy, up to 75cm (30" by 60cm (24") heart shaped leaves, with purple veins and shiny purple 4ft stems. With heat, water and nutrients this will compete with bananas.
It produces a tuber later in the season in its first year, and suckers and runners are produced freely when quite small. The runners are of the marathon type, running extrodinary lengths. The top of the tuber is above ground and should not be covered with compost or the stem may rot off. They do very well with their feet in water, and I plant them as marginals and in the waterfall plunge pools, where they assist in sucking the fish nitrate from the water, making it clearer.
They can be kept in a pot or tub in a dish of water, (empty the water out every few days to stop mosquitos). but for optimum growth will need a 15 inch tub. Alternatively plant out in well manured ground with humus and water gel granuals dug in. Like Bananas, they are gross feeders and like a constant supply of nutrients. I have found it possible to over feed which causes the leaves to collapse or distort and dry out.
I now feed with half strength Miraclegro every watering with a pinch of lawn feed (not the weed and feed type, or it will kill the Colocasia).. every watering
Colocasias, like Bananas, need a high nitrogen diet to produce the largest leaves. Most commonly available plant food tends to have lower nitrogen levels, concentrating on a tough, flowering plant.
I left two of my plants in the ground here at Chalk last year. I lost one, but the other sprouted again in late May. It is interesting as the most sheltered one rotted, while the more exposed one survived. The reason appears to be moisture. The frost sheltered one was under shrubs but exposed to rain, whereas the the frost exposed one was under the eaves on a north faceing wall.
Fontanesii overwinters better than many Colocasia, and is as good as Burgundy Stem in that it does not go into dormancy readily, and continues to grow down to around zero C.Iif it does go dormant, it doesn't require as much heat as Black Magic to get it to sprout.
Definately a plant worth trying, bringing that tropical touch to your garden. Another Wow! plant