I took some time tonight to plant most of my black mangrove seedlings into hanging planters. Here’s a shot of the plastic snap top container that I used as a germination tray.

black mangrove seedlings in germination tray
I tried a few different germination treatments, but the conditions for this group of propagules worked the best. I have this tray on a seedling heat mat in one of my indoor greenhouses. The rooting substrate (calcined clay gravel) was probably at around 76°. The tray was off to one side of the enclosure, so it only received moderate light. The little plantlets grew really well.

black mangrove seedling roots
There was very good root development. I did not add any fertilizer to the rooting substrate, so this growth was all supported with the nutrients stored in the propagules.

black mangrove seedlings in hanging planters
I planted the seedlings into the planters in pairs. I am interested to see how well they grow. This will be their first test of response to pruning: I pruned roots back to about 1 1/2″ long before potting them up.
Im interested in converting one of my aquariums to a riparium. So im wondering what do you use for substrate in the planter. Im guessing you put the clay balls first then a substrate on your choice?
Dalton,
Thanks so much for your comment! That is correct, the clay pebbles line the bottom of the planter cup so that the gravel substrate will not spill through the bottom.
I hope to offer planter gravel soon. I am working with another manufacturer to acquire an order of the right material and package as Riparium Supply. In the meantime, I suggest that one use a comparable planted aquarium product, such as Eco Complete or Fluorite. These are packed wet, so they are somewhat more awkward to use, but I find that I can fill around plant roots pretty well using a spoon.
Let me know if any other questions come to mind.
Regards,
Hydrophyte
nice. I have a red mangrove, but those black ones look really interesting. I can’t wait to see how they look in a year.