Why does my Arboricola have sap flowing out of it?
It's not sap. It is honeydew. The plant has either aphids, scale or a similar pest that gives off honeydew. It will drip off the plant like it is sap if it is a bad enough infestation. I would recommend treating the plant with neem oil. This article will help:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm
https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
I have this plant. Its leaves are covered with small brown dots. Some places look shiny, like it is sticky. I have found several on the plant and the plant table I have it on gets coated with a rough covering like a very fine dripping from the plant. The table is glass and I have to clean it regularly. Is this normal for the plant? It never really looks very healthy, as it sort of droops more than the ones I see other places. I would appreciate any insight you may be able to give me with this sketchy description.
Look for scale insects along the stem and on the leaves. That is the number one problem with this plant species. If scale is not the problem, you may have spider mites feeding on the leaf undersides. Look for little webbing on the leaf edges. Mist the foliage with distilled water at least three or four times a week. If this doesn't stop the sticky dripping, you may need to consider getting rid of it. In the meantime, an old sheet or tablecloth under the leaves to protect your table.
For help in dealing with these pests, here are some articles that you may find helpful: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm
https://www.gardeningknowhow.com/plant-problems/pests/spider-mite-detection-and-spider-mite-natural-control.htm
Why do the leaves at the bottom of the pot keep turning brown and falling off?
I would check the roots for root rot. It may be that this fungus has set in and the plant is dying that way. Here is more information on root rot:
https://www.gardeningknowhow.com/plant-problems/disease/treating-root-rot-gardening-tips-for-housplants.htm
When I prune the Arboricola plant, can I start a new plant from the clippings?
Yes, you can take the cuttings and root them. This article will help you with rooting the cuttings:
https://www.gardeningknowhow.com/houseplants/hpgen/using-cuttings-and-leaf-cuttings-to-propagate-your-houseplants.htm
Is a Heptapleurum Arboricola poisonous to cats and dogs? If so, how much would they have to digest of the plant to hurt them? I got a beautiful one as a gift and I wanna be safe.
They are poisonous, but most animals will leave them alone. Small amounts will make them sick.
My plant is losing leaves. The leaves have turned dark brown/black and fall off. The plant is located near a window, pot is large with proper drainage. I feed the plant once a month and water every 10-14 days. During the hot weather my city is experiencing, I spritz the plant. My Marginata is also losing a number of leaves. Both plants are large. I have been closing the blinds more than ususal to keep the sun out.
I would check the roots for root rot. It may be that this fungus has set in and the plant is dying that way. Here is more information on root rot:
https://www.gardeningknowhow.com/plant-problems/disease/treating-root-rot-gardening-tips-for-housplants.htm
I live in Michigan, northern lower peninsula. I would like to put my Schefflera arboricola outside for the summer. I have had this plant for over 15 years and it is very large. What temperatures will it tolerate?
If you move it outside, make sure temps are above 50 degees at all times and protect it from any direct sunlight shining on it.