Pachysandra advise please

I am working on a hillside behind my home. I dumped 4 tons of screened topsoil on the slope so that the grade is not as severe. Then I put in two flats (100 plants) of Pachysandra. Well, as long as I am watering twice a day I figured I’d put in 50 more plants. Then fifty more. So new they are about every 6 to 12 inches.

How long before they begin to spread? Should I fertilize once they are established? My gf offered cuttings from her pachysandra. I took 50 cuttings, dipped them in rooting hormone, and put them in peat pellets. How quick does pachysandra root?

Any other advice?