Misting the Ficus daily will add more moisture to the soil than you'd imagine, but does absolutely nothing for humidity, and a big tray of stones and water would be better, as long as the pot isn't touching the water. And you can never give them enough light - try a full spectrum bulb fluorescent just a few inches about the tree x 15 hours a day and see how it responds. When's the last time you repotted?

The oleander got scale this past year and I sprayed it with some stuff that got rid of it, but the oleander leaves are very dry and brittle now.

The problem with the oleander could be shock and an effect of the "stuff" you sprayed it with it could have burned the leaves and that's why they're turning brown.

Babywatson, I suggeest the oleander be cut back NOW...not in the spring. The plant grows slow and by springtime, it will be ready to grow anew.
I cut my own oleander back in November and it does grow new leaves, new shoots, through the winter in an east...then west exposure.
Water to drainage, then allow it to dry down...pay attention to any drafts from heat vents, or doorways that can abruptly change its soil moisture level. Put out of doors when warmer temperatures come back.

The ficus, it does seem to be getting sufficient light from all the sources you mention...even at this time of low sunlight, possibly it is getting too direct a light.
They don't like direct sunlight.

Like the oleander, does perhaps this sunroom serve as a 3-season room....the doors (hopefully not the windows or skylights) are opened and closed to give direct air currents on the plants. This can definitely cause what you describe.
I don't think either plant needs a moisture tray....just normal watering to drainage, normal letting them dry down.
Their drainage water not allowed to sit for any time in the saucer below. As long as they not growing, no fertilizer is needed.

JEANNIE you do not know what you're talking about! Ficus NEED very high light for many, many hours a day! For heaven's sake can you just post what you really know about? Just because some sad looking thing in an office gets by on less than high light doesn't mean they don't like or want it.

Let's play nice, Lucy, lol!

babywatson, the pesticide comment made earlier is a real one, by the way. Do you remember what you used to treat the scale infestation?

As Lucy asked, have you been taking care to re-pot your plants upon occasion....or (at least) root prune them? Soil/root environment changes dramatically after a year or two being held 'hostage' in the same container.

Oleanders grow quickly, by the way, if given plenty of full sunlight. Cut yours back in late winter/early spring.

Rhizo, sorry if things are unpleasant, but this is just the latest in a slew of plain wrong advice given by the poster. I'm sure she means well, but a little research might be in order before offering help to newbies who want their plants to do well.

Lucy, in the 3-season room she has her plants, where...at this time of season, is she about to get the light you profess the plant needs.

Her ficus is in a slowed down stage....it is not receiving the light you speak of.
Just because the sun is up....has no bearing on what kind of sunlight plants receive at this time of season.

Ficus DOES NOT LIKE FULL SUNLIGHT...giving such to a ficus is an invite to problems.
As the 3-seaon room does offer sunlight in a wide offering way...by windows and skylights....I contend the plant may indeed be receiving sunlight to a greater degree that is maybe causing what she is seeing in her plant.

She has divulged she has not done anything improper to her plant...yet the plant is dropping leaves.
That may be due to many things....light included.

Perhaps you could come back and tell us all, where she should attain this high light you suggest she should.
Leave the sarcasm at the door....

Actually, the ficus seems to be doing better recently. Here is what I've done:

Taken the screens off the windows so as not to cut down on any light.

Using a humidifier in the room.

Misting plant daily.

Using a grow light.

The plant really does get a lot of light--it sits right in a southern exposure all day long. I've also got bougainvillea and mandevilla vine growing there, and they are doing well. Though they are not flowering. But I guess that's too much to expect in winter.

Thanks for all your help, I really appreciate it.

Jeannie - Go to http://www.bonsaihunk.us/cultural.html and do some reading. Jerry M. is THE acknowledged ficus expert anywhere online and is a professional and internationally known grower. Take a look at what he says about lighting for ficus (and a whole lot of other info. on indoor growing in general).

Lucy, for the most part, we all....all of us, give to this site what we can offer. I don't think any of us has suggested we are experts...know all, see all....I certainly am not anywhere near an all-knowing person....I give what what experience I have and what I've learned....a lot from garden sites like this one...and I give it freely, not with any expectation of solving problems absolutely.

I have a houseplant guide...and for ficus, it emphatically suggests this plant NOT be given direct sunlight.
I have a benjamina and am very protective of it by putting it into an eastern exposure and putting it more in what sunlight I can give it. I wouldn't dare put in in my western exposure window....besides not having the room...because I think the plant would suffer.

A simple "I disagree with"....is often quite suifficient to get a point across--no need to throw barbs.
So let's just suggest you and I might disagree on some things now and in the future...and hope what info we do give helps in some way.

Mary, beware of the misting....not only is it practically useless for raising humidity in a room, but if you have a problems with foliage diseases....misting will certainly make the situation much worse. Your humidifier should do the trick. Truthfully, most common indoor plants do very well with the typical (dryish) inside humidity. Sounds like you've made some positive changes, though!

NOW! If we can only talk you into a little root pruning, lol!

jeannie, may I suggest that you use several sources when researching plant problems. Typical maintenance practices come and go, as technology improves our knowledge of how plants actually grow and how they respond to various environmental stimuli. I think that you may find that your plant guide might be outdated or maybe even incorrect in some instances.

There are nearly endless Internet sites ready and waiting to be explored. Of course, some of them are stuffed with ridiculous and false information, but as one learns to finesse an Internet search, it becomes easier to locate the truly informational and educational sites.

I have a benjamina in a south window , which of course gets full sun in the winter, when it seems to rejoice with the extra sun, but with the high sun angle of summer that window gets almost no direct sun and then it sulks and refuses to grow during the summer. Sort of opposite the way you'd expect most plants to grow with the more ideal temperatures and longer daylight of summer, I'd say. However having said "direct" sun, it has to be remembered that windows vary in the light they allow to enter, and in the north our winter sun is much weaker than a summer one would be or even a south window in the deep south most likely in winter, so it depends where you live as well.

Hi Jeannie - I would like to frame Rhizo's last note here for posterity! It's so true (the business about needing various sources of info. and the unfortunate fact that too many garden books have flaws (as do any such books). My information is gathered from many years of growing bonsai, some ficus, and a lot of listening/reading/watching of experts in the field. Your book may say what it does, it doesn't make it right, and because it's such a basic need of ficus anywhere (even if they survive low light) and because every serious grower I've ever heard of advocates high light, I will stick with it. Most I know have theirs within 3-4 inches of high intensity, wattage and lumen 'grow' lights of one kind or another, whether metal halide, high pressure sodium, fluorescent or something else, and their plants/trees are gorgeous, all other things being UNequal (water, fertilization, etc.). This shouldn't be personal, but maybe this helps - I'm probably a lot older than you (never mind how much :-), and so have had a lot more years to pick up all the useless trivia I spout here, and I'm sure when you get a few decades on, you'll feel exactly the same and be impatient with others too (of course we shouldn't be, but sometimes it's hard not to be!). Anyhow, I hope that your plants do well, and let's try to get along.