On Apr 3, 5:38*pm, wrote:
On Sun, 3 Apr 2011 14:29:32 -0700 (PDT), WesD
wrote:



Here is the scatter gun approach with follow up questions and
opinions. *Hope it helps.

That only the Schefflera are affected says it may be normal. *

Schefflera and philodendron.



You said they are neither over or under watered, I don't know if that
means you water a set amount at a set interval or if you also have you
checked pot drainage.

I gauge by sticking my finger in the soil. When it's dry about an inch
donw, I water. I used to have dozens and dozens of huoseplants and
watering was never an issue.

*I killed a dwarf Alberta Spruce, because the
drain clogged up and I thought the wilting was from too little water
when I had really drowned the roots. *But both having drainage
problems at once would be unusual.

I have gravel in the bottom of each pot.



What is the heat source for the greenhouse? *

Heat pump.

Is the greenhouse
attached to your home or standalone?

Attached. Stays about 66 degrees year round.



Dropping leaves sounds like too much heat or low humidity, but most
leaf drop happens when heat is turned on in the fall.

True.



Do you regularly feed with miracle grow? *I would not go wild with
feeding miracle grow - that stuff is heavy in nitrogen and is not slow
release.

Mostly on garden plants. Can't recall if I used it on the house plants
before.

Can't say I am a big house plant expert, so I am stumped already.

Some philodendron don't branch more tips, but keep growing on only 1,
some of the older leaves will drop eventually. A guy in Huntsville
had one growing in his cube around 3 walls with a tag marking the
growth of each Apollo launch.

Schefflera do drop leaves, but I don't know if it is annual or not.
The lobby of the building I used to work in had some large ones and I
noticed the plant care people and cleaning staff kept the fallen ones
picked up so there were never many on the floor.

One last hail mary. You said no insects found, but how closely have
you examined the underside of the leaf for some kind of aphid or other
non flying very small insect. Might even try a magnifying glass. to
check them.
Repotting would have agitated the leaves and revealed white flies or
other airborne insects.

Wish I could have been more help.