1)LIGHT REQUIREMENTS-The base of the stems can be in shade but the tips need full sun to bloom/fruit well. To root cuttings shade is best but once there established or well rooted move to a brighter spot.
2)TEMPERATURE/CLIMATE-They will get damage if below 40 degrees for extended periods of time and severe damage if below 32 degrees for any length of time. Eventually they may be big enough after one growing season to be planted in the ground. In that case be sure you live in a frost free zone 9A and up. If you decide to plant in the ground they will need something to climb-a fence, wall, shade structure. If it only freezes slightly in your area in evenings a teepee made of 3 poles and plastic over the top might be enough protection outside.
3)FRUIT HARVEST– The fruit is ripe by July -August through all the way up to maybe December depending on how warm your daily weather was. You can tell they’re ripe when there reddish or pink on the outside of the skin or yellow in the case of (Selenicereus Magalanthus), and you can easily push in on the fruit with your finger and its soft like a ripe Avocado might be.