There is a Heptapleurum plant in the office and it has about 8 branches with clusters of 'bobbles' along each branch. It is continuing to produce new branches with leaves too. No one seems to know if these are flowers or what to do.
Yes, they do flower and it sounds like yours is flowering. The flowers vary depending on the variety. This link has some images of the different kids of flowers the different varieties get:
http://www.flickr.com/search/?q=schefflera+flower
I use containers that have a water reservoir underneath for plants that like those conditions. I had a beautiful 6 foot umbrella tree, but the vine weevil killed it.
For a south facing window in a conservatory, I would suggest taking a look at Citrus trees. South facing should give them more than enough light, the conservatory should stay plenty warm and the water reservoir would keep them watered to their liking.
The benefits would be that they are lovely trees on their own (and there are many varieties bred specifically to stay under certain heights for indoor planting), they get the most lovely smelling flowers and it is possible to grow the fruit indoors with the right light (which it sounds like you have).
I have a second plant that seems to be covered in sticky, sugary sap and I found brown dirt on the underside of a new leaf. How can I get rid of the pests or disease that is affecting it? An umbrella plant I had recently lost all its leaves, which yellowed and fell off, and I noticed the stickiness on that also.
It sounds like an issue with scale bugs. This article will help you with that: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
We would also suggest using neem oil to treat the scale, as it is quite effective and safe. This article has more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
My umbrella plant has green and blackish small insects (about 2-3 mm). They are affecting new leaves, which become distorted and shrivelled. I have used liquid soap but not to much effect. What should I do?
It sounds like it might be aphids. This article will help with that:
https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm
I would recommend neem oil as a possible insecticide for them:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
Since we transplanted three umbrella plants, we have been getting yellow mushrooms. Have tried different things to no avail.
These articles will help:
https://www.gardeningknowhow.com/houseplants/hpgen/getting-rid-of-mushrooms-growing-in-houseplant-soil.htm
https://www.gardeningknowhow.com/lawn-care/lgen/eliminate-mushrooms-in-your-lawn.htm
I bought a scheflera plant (umbrella plant) and have had it for 4 years. It now reaches the ceiling in my living room and is growing at a slant. I don’t want to cut it - is there any way around this? If I cut it, how do I do it and how much do I cut? Please help, we all love this plant.
These plants will tolerate a heavy pruning, but if you want to play on the very safe side, do not trim more than 1/3 of the plant back in one season.
Umbrella plant is oozing sticky substance. Tiny brown spots underneath? Mites?
Not mites. It sounds more like it could be scale. Neem oil will help with these pests (including mites). Here is more info: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm