Q.Sunshine/New Guinea Impatiens
I want to plant 10″ potted impatiens in garden for instant color and coverage. Any suggestions to encourage spreading and longevity besides adhering to regular fertilizing and watering, given they are larger plants?
Plant the Impatiens about 18 inches apart for a nice mass display.
Here is an article to refresh you on the care requirements, which you seem all ready aware of.