Question
I have a money tree and some other kind of indoor office-type plant about 5' high, and an orchid.
Both my money tree and orchid are starting to get yellow in their leaves, and the money tree is losing leaves.  I don't overwater them, and suspect they need fertilizer.  
   The other office-type plant has long green leaves with thin yellow bands running the length of each leaf. The leaves grow directly off the trunk, much like a palm. Its okay, but I think I should fertilize it.
    Suggestions?
    Thanks.

Steve

Answer
You can use a diluted liquid fertilizer with your watering, but it is likely not the cause of the yellowing of the leaves and the loss of foliage.

Nitrogen deficiency (which happens first with lack of fertilization) often manifests iteself through a light green growth of leaves. New leaves are smaller, thinner than normal leaves, and eventually growth is stunted.

Leaves which yellows and die are most often due to a rapid change in temperatures, humidity, watering pattern, or sunlight. It is not uncommon for indoors plants to loose leaves due to low humidity in winter (which is actually no better in summer due to the use of air conditioners).

You can increase humidity around plants by placing them on a container filled with stones. Water should be poured over the stones and left in the container up to but not beyond the level of the stones. The water would evaporate and increase humidity around the plants. E.g. the water in the stone basin would be for humidity only (not for watering). The water level should not exceed the level of the stones (the plant should not stand in water).

Plants which are watered regularily can still be short of water if root bound. Some plants respond better to being rootbound than others. It is typically beneficial to repot into a larger pot (with new fresh potting soil) if the above happens.

Water on a regular schedule (say 1-2 times per week) using water one time and a water/fertilizer mix the second. It is better to use a diluted fertilizer mix frequently compared to a strong fertilizer mix infrequently. If in doubt, read the lable and use the mix 1/2 strength as above, or 1/4 strength with every watering.

Some plants, even if they are indoors low light plant need some kind of regular light from a window or a close lamp. Overhead flourescent lights may not be enough for all plants.

I.e.
- move plants to a draft free location, away from air vents, and preferably near natural light souces.
- repot to larger pots (one size up)
- water regularily with diluted fertilizer applications

Generally, low light plants like the ones you describe are not heavy feeders and less is better in this case.