#1 thing is starting with a strain bred to finish outdoors on time. You need an 8 week or less outdoor or indoor-outdoor strain. Try a Skunk or Northern Lights.

Your spot on the cliff may be very visible to helicopters, plus cliffs attract hikers and rock-climbers. Pots are quite obvious. Try a more discreet location, and prepare the soil with plenty of composted manure or topsoil well before you plant.