Can HolidayGrow be added to a pot that is already planted?

It has to be mixed in before planting

HolidayGrow has to be worked directly into the substrate before planting. That is the only way the hydrogel can spread evenly through the root zone.

Mixing it in later is not recommended

If plants are already in the pot, the gel can no longer be distributed properly and cannot develop its full water-absorbing capacity.