Phlox Requirements

Tall, stately phlox is striking in a bed of its own or as a backdrop to lower-growing flowers. Phlox is available in a range of colors, with each flower stalk covered in many bright blossoms. Phlox is also a fragrant flower, making it suitable as edging around patios and seating areas where you can enjoy its sweet aroma. Caring properly for your phlox ensures it will continue to bloom profusely each summer, providing at least six weeks of color each year.


Phlox requires at least six hours of sun a day. While it can grow in partially shaded areas, it is more prone to powdery mildew if it receives minimal light. Avoid planting it in areas shaded by trees or shrubs, as the tree roots may prevent the phlox from accessing soil nutrients.

Soil Condition

Phlox requires beds that are well-draining but rich in organic matter. Working compost into the soil prior to planting provides the needed drainage and nutrition. A top dressing around the plants each spring of more compost helps replenish this organic matter.


Phlox does not require constant fertilization, though a spring application helps encourage healthy foliage growth. Fertilizing again once flowers begin blooming leads to a longer, more profuse flowering period.

Air Circulation

Areas close to fences or walls may lead to disease due to poor air circulation around the plants. Because of the denseness of phlox gardens, powdery mildew is also a problem in some areas. Pruning the plants and growing disease-resistant varieties prevents most problems caused by poor air circulation.


Phlox needs moist soil to thrive, though it cannot tolerate constant soggy conditions. Mulching around the plants helps preserve moisture in the soil, preventing the need for constant watering. Like most summer flowers, phlox thrives with 1 to 2 inches of water a week, provided by irrigation or rainfall. When possible, phlox should be watered at the base of the plant as wet leaves make the plant more prone to disease.


Pruning phlox is optional, but minimal pruning improves the look of the plant and encourages better air flow throughout the foliage. Generally, each phlox plant should be pruned to six main stems in early summer and spent flower stalks are later removed. Staking taller varieties is also simpler when the plant is properly pruned.

Keywords: phlox requirements, perennial flowers, how to care for phlox

About this Author

Jenny Harrington is a freelance writer of more than five years' experience. Her work has appeared in "Dollar Stretcher" and various blogs. Previously, she owned her own business for four years, selling handmade items online, wholesale and via the crafts fair circuit. Her specialties are small business, crafting, decorating and gardening.