I received a desert rose (bonsai?) as a gift and it’s doing quite well, but it hasn’t started flowering yet. I live in the US northeast, so I keep the plant indoors under a grow light (I don’t get very good light in the house) and I water it every 2-3 weeks. I’ve read that these plants need fertilizer in order to flower, but I’m getting conflicting information on what to feed it - bone meal, 1-1-1, 6-6-6, 13-13-13. If anyone could clarify what (and how) I should be doing it would be very much appreciated. I would also welcome any general advice on caring for this plant.

Adenium obesum is a Summer bloomer and like having some extra phosphorus to help with that. Phosphorus or P is that middle number on the fertilizer. A solid, time release organic fertilizer is fine but if you go the liquid route, only add it every other watering and at half strength.

Remember, they are a succulent and don't need to be watered until the pot is dry nor given too much food. Perhaps Summer it outside on a western or southern exposure if you can, but if not, succulents do great under lights, which you mentioned. Remember, this plant is Winter dormant so cut back on water and stop feeding then until Spring returns.