For me, the most anxious moments are waiting for the seeds to germinate, or a leaf or cutting to root or the first bloom on a new plant. In the case of cacti or succulents for which I have a very bad track record - waiting for the first sign of impending death. Other anxious moments occur when plants are enroute from a vendor and weather is turning cold - question is whether the plants will arrive in good condition?
However, anxious moments are more than offset by the pleasure in seeing seeds germinate, leaves and cuttings root and the first bloom on a new plant.
