Hi locker,
to All Things Plants!
Dwarf Umbrella Tree (Heptapleurum arboricola) are grown as landscape plants here in Florida in bright locations with protection from hot afternoon sun and they do like high humidity and consistently moist soil. Your first photo shows a plant in-ground and it looks to be quite dry so I'd say give it a good soaking every couple of days and it should perk up. I just noticed your location listed as zone 4b so just be aware that Schefflera will not survive winters that far north. You can dig and pot it up to bring indoors before cold weather hits but be prepared that it might drop leaves for awhile due to transplant/location shock.
The plant in your second photo may be dropping lots of leaves due to a variety of conditions. Soil may be too dry, the lack of air circulation around the plant, or minor shock due to transitioning from a greenhouse/nursery situation to a home climate but it should be okay if growing conditions are met. Give it a location of the brightest light available and keep the soil moist but not soggy and it should recover and sprout new foliage. Keep the plant away from heating vents and to raise humidity levels around the plant you can place the pot on tray of moist pebbles; as the pebbles dry, replace with a little fresh water.
Again, Welcome!
Lin
