Hi cluelessjo,
to All Things Plants!
LOL, we are all clueless about plants some times ... even this old gal who has been growing plants for @ 48 years!
Dwarf Umbrella Tree (Heptapleurum arboricola) grow as landscape plants here in Florida and they are pretty tough. After enlarging your very last photo of the entire plant, I tend to agree with everyone else that you tree may need a larger container. You can slip it out of it's pot and see if the roots were crowded in there and if so, pot it up with fresh soil into a larger pot. You might find that you have more than one plant crowded in that container; it seems that's how the nurseries grow them anymore, they stick three or four small plants into a pot to make for a fuller plant and as they grow larger, the roots get all tangled together and it does look like one wide plant. I had a large (@5 feet tall and 3 feet wide) Schefflera one time and decided to repot it into fresh soil and got 4 separate plants from the one. The roots and trunks were sooo tangled together that I had to actually yank them apart and I potted them up separately.
Schefflera are tropical plants and they like high humidity so that could be the cause of the leaves turning brown and dry with crispy edges. You can raise the humidity around the plant by sitting it on a tray of moist pebbles, adding a little more water every so often as it evaporates. Another way to help with humidity is to get a spray bottle, fill it with water and mist the tree once in awhile. Keep it out of drafts and away from heat vents, which causes the plant to stay too dry also.
Good luck in your new Colorado home and I hope that your Schefflera perks up and brings you a lot of enjoyment.
Lin
