I am converting a small fountain and pond into a rock garden. Space to work with is about 2' x 4'. So far, I have Anouk Lavender in the top-left corner, Blue Star Juniper in the bottom-right corner and Cooper's Ice Plant in the lower-left corner. I just purchased a rosemary, Angelina Stonecrop and Blue Spruce Sedum (seen in middle photo's foreground), but I'm unsure of where to place them, if at all. It a high sunlight location in zone 7A and gets quite hot in the summer. Bonus points for evergreen plant suggestions.
I'm sorry to tell you that your blue star juniper will more than fill that space on its own - the lavender won't take up much room widthways, but the Delosperma (ice plant) would also fill up most of area, so really, there isn't room for anything else. I suggest you remove the blue star juniper altogether - it will spread all over the plant behind it where its planted now and is altogether too large for such a small area. When choosing plants, checking their eventual spread as well as height prior to planting is important.
Blue spruce sedum will spread up to 12 inches all round; rosemary will be a large shrub, 6 x 6 feet, so you can see that area is way too small for all these plants. Hopefully, you can find somewhere else for most of them.
Rock plants are usually much, much smaller subjects - Armeria maritima, for example, is an evergreen perennial with grass like foliage and bright pink flowers in spring, but it doesn't get much bigger than 4-6 inches wide. Others, like Euphorbia myrsinites, get about 6 inches tall with a spread of around 10 inches, whereas Iberis sempervirens can spread up to 2 feet - these three are evergreen. Some guidance can be found at Rock gardens: plants.
I have a bit of a hill in the back yard.Was very hard to mow,mostly mowed the dirt.The area gets sun all afternoon and can get very dry.I hauled a bunch of rocks,different sizes shapes and colors and tried to create what they call a "rocky outcrop" almost like a waterfall effect.Filled it all in with river rock and planted Candytuft and Blue Festuca,the Candytuft will bloom this spring and the Festuca lasts all the way till winter.They propagate very quickly so their filling in nicely. The book I referenced is by H.Lincoln Foster, Rock Gardening.I have taken pictures of my rock garden would like to post them for the site, need help!