Set the Miltonia's pot in a south- or east-facing window where it can receive bright, indirect sunlight. The spot should maintain a temperature of 75 to 80 degrees Fahrenheit. If the temperature surpasses 80 F, or the leaves turn yellow, shade the window.
Water the Miltonia twice a week during the summer growing season, and reduce watering to once a week during the winter. Water the plant in the morning, adding enough so that the excess comes out of the drainage holes in the bottom of the pot. Do not let the orchid dry out.
Apply orchid fertilizer to the soil when it is moist. Mix 1/2 tsp. of fertilizer with 1 gallon of water and apply that once every two weeks, or mix 1 tsp. of fertilizer with 1 gallon water and apply that once a month.
Keep the humidity around the plant at 55 to 65 percent. Install a humidifier near the plant or use a humidity tray if your home has dry air.
Repot the orchid into the next pot size up every two years, or whenever the existing potting medium begins to break down. Remove the orchid from its existing pot after it has bloomed, lower it into the new container and backfill with orchid potting mix.