Question
OK, lets start with my first guy (Dendro.) I have had this plant for YEARS (probably about 6) It flowered once. I have been taking care of it well enough for the leaves to look healthy until recently. I live in Maryland. So, during the summer months I usually keep it outside and bring it in in the fall. Right now it's near a window facing N-E., and the humidity is about 25-35%. I do use a humidifier, but I just can't get the humidity much higher. Recently, I noticed the leaves are starting to wilt on one side. I have another shoot in the pot that seems to be doing better, this guy is pointing towards the window. Anyway, any info you can give me to help this guy stay alive and possibly flower again would be great! I also would like to know about re-potting and splitting? it.
Next, we have my new plant, Phalaenopsis..I got this guy on Valentines day (so we are talking two weeks) I put him near a window that's shaded and watered him when it was dry. Now a few flowers have dropped. I also  have a little spot on one of the leaves, reddish-brown in color. Please help keep these guys alive, I just love my flowers!! Thanks :-)

Answer
Thank you for the details Jessica.  That dendrobium is a deciduous dendrobium.  It requires a rest period during which it loses some or all of its leaves.  If it is watered much during its rest period, it goes back into growth and into decine over a few years because it wasn't permitted to rest.  If it isn't permitted to rest, each new growth will be smaller than the last.  A healthy dendrobium will have stronger, larger growth with each new growth.  Humidity is good but needs to be measured next to the plant as that's the only place that counts.  If it is too low near the plant, create a pebble tray with a little water in it and set the plant on top of the pebbles.  This will add to its humidity. Mist the plant in the morning in lieu of watering during its rest period.  Dendrobiums like to be tightly potted so it can stay in its pot. You may add inorganic material to the existing potting mix as needed (such a perlite, lava rock, or charcoal) but rarely would you repot or divide a dendrobium.

Phalaenopsis is an entirely different type of orchid, has no rest period, and needs annual repotting.  Phalaenopsis flowers last from 2-4 weeks and, if it came in flower, it may be at the end of its flowering period. When it's done flowering, you need to repot it in fresh orchid pottting mix.  The reddish brown spot may be a fungus called rust-- after its color.  If that is what it is you should be able to rub if off from the leaf.  If it is another type of fungus, I suggest removing that part of the leaf to prevent spread. Water your phalaenopsis once per week in the morning and you may feed it weakly weekly (ie 1/4 tsp of plant food per gallon of water).  You may want to accecc the American Orchid Society (AOS) web site where you may find information on growing different types of orchids.