Is the Prayer plant a Maranta leuconeura ? Green oval leaves with herringbone pattern?
They tend to spread out horizontally.
I trained one up around a moss pole. It looked good for a couple of years but it got too high, and a bit untidy.
I have just taken some cuttings with a view to starting again.
You can train them, with the help of wire or string, up a moss pole or up a trellis. Or even hanging down off a shelf/out of a hanging basket.
You can also keep cutting back the horizontal growth/vines and plant the cuttings back into the compost in the pot. Making it appear more 'bushy'. I do this with my Inch plant (Tradescantia zebrina).
