A tank consists of a series of cycles, ammonia, nitrates, nitrides themselves must cycle in addition to all the bacterial, enzymes etc which must be given time to develop. Water changes are used to keep levels from spiking to prevent harm to fish and other livestock. if this is a plant only tank, there should be no reason why dosing could not start today for the plant development and intake of NPK should run independantly. If you are cycling with Ammonia however, the risk of getting plants burned is a there as it is strong so be mindful of dosages over the days/weeks until the ammonia levels gradually diminish.
"I am Groot", the faithful protector