Generous 6" (15cm) deep aluminium
Plunge Propagating Trays designed to create an area for multiple uses -
For 'plunging' pots, fill with coarse sand or gravel (e.g. for alpines) in order to keep them stable and moist.
Fill with washed, horticultural coarse sand, and turn it into a heated propagating tray by adding a soil warming cable.
Fill with soil and compost and create a deep growing area to cultivate a huge rang of shallow rooted crops.