Ammonia during fishless cycling can kill plants. This is simply because more than a whole day's worth of ammonia is added all at the same time. It's the high level of ammonia until it can be processed which harms sensitive plants. When there are fish in the tank less ammonia is made and it is 'added' in tiny amounts 24 hours a day not a huge amount all at once.
We recommend either
a fishless cycle with no plants then plant the tank when it's finished (usually when only a few slow growing plants are intended)
or
plant a lot of plants and do a plant cycle.
We recommend either
a fishless cycle with no plants then plant the tank when it's finished (usually when only a few slow growing plants are intended)
or
plant a lot of plants and do a plant cycle.