Question WHEN IS THE BEST TIME TO PLANT CREEPING PHLOX? Answer Creeping phlox is a tough plant! You can plant it either spring or fall. If you plant it now, you will be able to enjoy it early spring when it flowers. Tags: CareDesignFAQProjects Related Questions Will it hurt my plants if dogs pee on them? Purchased First Editions Vanilla Strawberry hydrangea tree almost 2 weeks ago. Planted it on the ground, full sun (morning)area. Now, the bottom leaves are turning yellow. I make sure that soil doesn’t get dry. What to do? What is the best food to give my Campfire rose? I planted two Endless Summer hydrangeas and the leaves are turning yellow and not doing as well as the other two. I am not sure what to do.