Orchid cactus, or Epiphyllum, is a flowering tropical plant you can grow outdoors in the summer and continue to enjoy indoors in the winter. Although it's a cactus rather than an orchid, its flowers are just as lovely. Varieties come in a rainbow of colors, from white to red to orange and purple. Orchid cacti grow in trees in their native Central American rain forest environment, where they draw nutrients from their host plant. If you take a clue from nature, you'll see that these plants need lots of air circulation, little if any soil and minimal water.
Gardening the Orchid Cactus
Add equal amounts of sand, perlite and shredded bark to your potting soil. For a 1-gallon pot, use 1 cup of each of these amendments.
Empty about 1/3 of the potting soil combination from your pot and place your orchid cactus into the pot. Refill the pot to within ½ inch of the top with the potting soil mixture you removed and pat it down gently before you water it thoroughly. After planting, water your orchid cactus once a week and allow the potting mixture to dry slightly before you water it.
Place your potted orchid cactus on top of a plant saucer filled with small pebbles. Keep the humidity higher by adding water to the saucer when the water in it has evaporated.
Keep your plant in an area that receives filtered sunlight, such as under a tree or arbor. Orchid cacti prefer temperatures between 50 and 86 degrees F. They require temperatures between 50 and 55 degrees F in winter to encourage blooming the following summer.
Fertilize with a liquid plant food with an nitrogen-phosphorous-potassium (NPK) ratio of 5-1-4 throughout the summer every time you give your plant water. Avoid fertilizing orchid cactus during the winter.