Now. Apply the nute pack to all rooted plants at 1.25 tsp / gal. Mix well for about a minute, let the talc settle for a few minutes and water in off the top (leaving the majority of talc in the bottom of the mixing vessel. You can also dunk rooted cuttings in this solution prior to planting.
Use the nute pack again whenever you transplant, and use the root and foliar once every 7-10 days as a foliar (with an organic surfactact i.e. .yucca extract) and drench to saturate (no runoff)