It is quite normal for plants to shed leaves at this stage. If it is just the odd leaf, I would not worry about it. They look pretty heatlhy!

For my outside plants I mixed a good quality pro mix, from Home depot if that is what you have there, sheep manure, marine compost, and some cow manure. I also added a handful of bone meal, (about a 1/4 c per gallon soil) some FF American pride, and some dolimite lime to buffer the soil, and raise the ph. Peat moss when it breaks down can be very acidic and it is hard to correct that once the plants are in the ground.

Hope that helps you.

peace
Life,
J-angel
greenpassion.org