I've just fed my palm tree with liquidised bananas and green leaf veg. I liquidised 4 very soft, going brown bananas and the leaves, along with some cold tea to make it into a liquid consistency. My palm tree now lives acoss the road, outside the old folk, women's institute etc centre. I asked the women's institute ladies if they'd like it across there as it kept getting moved and messed with by the dossers in these flats.
There was about 1 litre of the liquid food. I used a trowel to cover the liquid as best I could with the tree's soil.