Root nutrients in unborn plant

If by root nutrients you mean root stimulators, i would wait for at least 1 week but you are free to do as you please, just keep in mind that during the first week the plant is still using the energy stored within itself to grow and using the root stimulators might help or it may harm, in conclusion i would say wait at least 2 or 3 days after you see the plant coming thru the soil. Hope it helps and if you don't mind chosing answer it helps a lot in grower of the month competition. Thanks and good luck growmie.