You can root straight into the sand on the bench, but I wouldn't. roots
quickly get amongst the wires and mess up the level of the wires. better to
rot in a box of media. I would use 1/3rd peat, 1/3rd sand and 1/3rd
pearlite, in a box a couple of inches deep.
It will be easier to get the plants out.
but still better to root in cell trays,

--
David Hill
Abacus Nurseries
www.abacus-nurseries.co.uk