Transplant the orchid to a larger pot while it's dormant. Use a heavy pot with a drainage hole, one size larger than the old pot. Fill the pot half full with non-soil potting medium like peat moss or fern matter.
Tip the orchid pot on its side and tap to loose the potting medium. Grasp the orchid at its base and pull gently to take it out of the old pot. Brush away potting soil, spread the roots and trim any dead, damaged or broken roots.
Spread the orchid roots over the potting medium in the new pot and pack more medium over the roots and around the base of the orchid. Leave the crown of the orchid above the soil level. Continue adding potting medium until all roots are covered. Push an orchid stake into the medium next to the base of the plant to secure the potting medium, and for future support of the orchid spike.
Put the orchid in a spot that receives indirect or partial sunlight. Orchids enjoy morning light and afternoon shade, or the indirect light of north- or south-facing windows. They also do well under all-day artificial light.
Mix water-soluble orchid fertilizer at 1/4 strength. Pour 2 inches of this water/fertilizer mix into the orchid potting soil, avoiding the crown and any remaining leaves.
Put the orchid on a schedule of 2 inches of water a week and fertilizer mixture once a month.