Allow cuttings to harden off for about one week before planting. Plant cuttings in a clean dry potting soil mixture. It is recommended that the best potting mix is 3 parts commercial potting soil and 1 part small to medium pumice. If pumice is not available, use bark chips or perlite. The soil must hold moisture but drain quickly.
Plant cutting upside down for best results. Plant the small growing end 1 to 2 inches deep in the soil. Two (and only two) of the leaf serrations should be below the soil level. Place the pot in a bright shaded place. Rooted cuttings should not be allowed to dry out. Water lightly at first and then water once a week. The only exception is in the winter months when the cactus “rests”. Water during this time about once a month.
Another Method for Faster Rooting:
You can put the cuttings in a plastic cup with a little water at the bottom. Then put another plastic cup over it and tape it to create humidity inside the cup. Then put it at the window with filtered sunlight . It should has root in 2-3 weeks
The rule in raising Epiphyllums is to not let the roots completely dry out. Allow the top 1/3 of the soil to dry out before watering. Overwatering is the greatest danger in raising these cacti.
Orchid cacti have natural growth cycles during spring and fall. After flowering, the plants may appear a little wilted but do not increase watering more than the usual watering schedule. During the winter, to encourage heavy flowering next year, place cacti in unheated bedroom or garage for 2 or 3 weeks. Make certain they still receive filtered light.
Cacti do best in filtered sunlight. They seem to like a few hours of full morning sun, but never full midday sun. If wintering your plants in the house, place them in a cool (40 plus degrees F) room. Lights should not be turned on after daylight hours. If lights are turned on after sundown, flowering for the following year may be delayed or affected.
Watch your cacti for over/under exposure to light. Sunburned or yellowish wilted growth means your plant is getting too much light. Weak leggy growth means your plant is not getting enough light. Fresh green growth, (light to dark green) with slightly red edges indicates that the plant is getting the right amount of light.
Epiphyllums like 40 to 90 degrees F. during the summer. Plants subjected to 32 degrees F. and below die back.
A balanced fertilizer (10-10-10) should be used. Do not use a fertilizer that has a nitrogen content of over 10%. To encourage flower development, use 2-10-10 the last week of February and again at the end of October.
Usually Epiphyllum must be root bound before they will bloom. This means their roots must fill the container before they will produce blossoms. If plants are in a 4 inch pot they will flower faster than if grown in a 8 inch pot. Flowering begins in late April (white and yellows), May (pink and reds), June and July (deep reds and purples).
Source: OSU Garden