I'm so sorry about tthe plants you lost! I confess, I'm a serial killer of unplanted plants, whether they roast to death on a summer sidewalk, or freeze to the back steps over the winter. Hope you're not out too much money -- and that your garden bounces back.

Thanks turquoise & datdog-- My garden is on a hill and the terraces were there when my partner and I bought the property about 7 years ago. The terraces make the space easier to use but they were done at least 20 years ago, not very professionally, and the landscape timbers are sagging and rotting. I'm dreading the day in the not-too-distant future when they will need to be replaced! BTW I grew up and first learned to garden in upstate New York, and I don't miss those long winters one bit! Datdog, if you're in a solid zone 7 you should be able to grow fatsias. Mine have taken single digits (6 & 7 degrees) without leaf damage. They are generally rated as hardy to zone 8 but they are tougher than people think. In zone 7 they do need to be in a fairly sheltered location, mulched well in the winter and should be placed where they won't receive direct sun in winter. Being in the city, I'm fortunate to have some buffering against the really cold temperatures because of the urban heat island--we haven't had temperatures below zero since 1994. But I also know people who live outside the city and have even bigger fatsias than mine.

Dianthus barbatus. Sweet William.

Even here in the U.K. this shrub is recommended for a shady position so they definitely don't want too much sun. Regarding the planting I think you have rather gone overboard. This plant is a tough unfussy creature which will grow in pretty much any soil. They are used in places like supermarket car parks and school grounds. It copes with dry soil and urban pollution. It would be best just being plonked straight into the ground without all the potions.