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 HOW DEEP DO I PLANT CORAL MAGIC CRAPE MYRTLES? What time of day should I plant The Original Endless Summer®? How do I prep the space? Do next years blossoms come on new or old growth? I have three Endless Summer Hydrangeas in different locations around my house about 20 minutes north of Chicago. The plants all seem healthy and continue to grow but have yet to produce any flowers. Back on Fourth of July weekend I gave them all Dr Earth acid lovers fertilizer hoping this would give them the boost that they needed. I have yet to see any results. Any assistance you could offer would be greatly appreciated.