Phlox is a faithful perennial with hundreds of varieties that grow in a wide array of climates and spaces. Growing well in pots or beds, Phlox is a low-maintenance choice to plant in large swaths throughout the garden. It comes in a variety of heights and nearly every color of the rainbow to complement any garden design. Phlox is one of the few garden plants that comes in a true shade of blue. 

The Same Plant, Different Sun Requirements

Phlox is available in two main varieties: Garden (or meadow) Phlox and Woodland Phlox. Garden Phlox performs best in full sun and can reach heights of up to 4,’ while Woodland Phlox prefers cool, partial-shade areas and stays more compact as it creeps along the garden floor. Both thrive in zones 3-8 and neither variety tolerates excessive dry or hot locations.

Planting and Care

Plant Phlox in the cooler months of spring or at least 4-6 weeks before the first frost of fall. Choose the correct location, giving consideration to the specific variety’s sunlight needs. If planting in southern locations, choose varieties that need partial shade to protect from the strong heat of the sun. 

Dig a hole as deep as the plant’s pot so that the root ball sits level with the surface of the soil. Add a generous helping of compost to the hole before inserting the plant. Fill in the soil around the plant, tamping it down gently, and water deeply to help the plant settle into place. Plant additional Phlox at least 18-24”’ apart to allow for mature growth. 

Phlox will need weekly watering of at least 1” of water per plant. Your new plant will not need any fertilization until the next spring when it will benefit from a dose of granular fertilizer before breaking dormancy. If planted in a pot, Phlox requires more frequent watering and will need to be repotted as it outgrows its container.

Phlox does not require maintenance pruning, but it is important to remove any dead or diseased branches throughout the growing season to keep disease at bay. In late fall, prune the plant back to 2-4” to allow for new growth the following year. In colder climates, offer your plant a covering of compost to help it sustain winter temperatures.

Phlox can become quite dense, so dividing every 3-4 years will refresh the plant and help create new plants for your garden. Dig up the plant in spring and divide it with a sharp spade into two clumps containing both roots and foliage. Replant as you would a new plant. Or to create new plants during the growing season, take 4-6” cuttings of the plant, strip the lower foliage, and dip in rooting hormone. Place this new cutting into a 4” pot and keep the plant moist and shaded. When the Phlox cutting begins to grow, you may transplant it to a new location in the garden, being careful to water it well to avoid transplant shock.

Four favorites for us this season are all from the Woodland variety and include: Candy Stripe, Crimson Beauty, Emerald Blue, and Scarlet Flame.