Question
I recently purchased an orchid and I must admit I know nothing about them. The orchid has been in my office, and unfortunately I have no window in my office. I had not watered my orchid in some time and it felt very dry Friday when I left work so I watered it at the bottom to allow the roots to soak in the water. Yesterday when I returned from the weekend one of my orchids' leaves had developed a "gooey" spot that felt almost gummy. The leaf is still green but the spot appeared somewhat translucent. I moved the plant to our lunch room with large windows but well away from direct sunlight. Today I arrived at work and the gooey spot had spread to nearly the majority of the leaf! I am concerned for this plant. I love orchids and have always wanted to grow them and have them prosper. Please help me, I don't want to kill this plant!

Answer
Ashley, the spot is most likely a bacterial infection.  It occurs most commonly when a plant is watered late in the day and a bit of water stands on the leaf overnight. While the leaf will naturally fall off, I would be concerned about it spreading to other leaves.  Cut the leaf completely off well below any signs of leaf rot and seal the cut ends with sulphur or a copper based fungicide if possible.  Do not water for several days and then only in the morning, avoiding getting water on the leaves.  

When the plant goes out of flower you need to repot it in an orchid potting mix.  This is a special potting mix just for orchids.  There are several types available.  Get the kind with the coarser particles including fir bark.  Before you remove the plant from its pot for repotting, soak a portion of the fresh new orchid potting mix as dry fir bark is water repellant.  Check the roots and remove any that are mushy before repotting.  Use a plastic pot with lots of drainage holes in the bottom for repotting.