Fort Hill Creeping Phlox
A Sun-loving Carpet of Pink Flowers
This low-growing perennial brings a burst of color to sunny slopes and the front of the border garden.
Fort Hill creeping phlox (Phlox subulata 'Fort Hill') is a cultivar of moss phlox, a low-growing, mat-forming perennial plant native to North America. Fort Hill creeping phlox has vibrant pink blooms and dense, soft green foliage that spreads to form a thick, soft ground cover. Masses of delicate, 5-petaled flowers cover the plant in April and May, attracting butterflies and pollinators while brightening up gardens and slopes.
Give Fort Hill moss phlox plenty of sunshine (6+ hours of direct sunlight per day), well-draining soil and consistent moisture. Creeping phlox is relatively pest and disease resistant, and does not suffer from powdery mildew to the same extent as other types of garden phlox. According to Rutgers University’s list of Landscape Plants Rated by Deer Resistance, deer can occasionally severely damage phlox. It is also a particular favorite of rabbits, who will chew the plant down to the ground.
Fort Hill creeping phlox (Phlox subulata ‘Fort Hill’)
How to Plant and Grow Fort Hill Creeping Phlox
Location: Select a well-draining site with full sun for best flowering. Fort Hill creeping phlox prefers a sunny location - it can grow in partial shade, but flowering will be diminished.
Soil: Fort Hill creeping phlox prefers moist, well-draining soil and can tolerate a variety of soil types, including clay and sand. Avoid planting in wet, poorly-drained sites.
Planting: The best time of year to plant Fort Hill creeping phlox is in the spring or fall, giving the roots time to establish before the onset of extreme hot or cold weather. Phlox is widely available at most nurseries during the spring and may be sold out by the time autumn comes around. Water deeply after planting (for more information on watering, read “How to Water your Plants”.
Spacing: Space Fort Hill creeping phlox plants 12 - 18 inches apart on center (12 - 18 inches from the center of one plant to the center of the next plant). Try this handy plant calculator to determine the number of plants required for your garden.
Watering: Keep the soil consistently moist, especially during the first growing season. Once established, creeping phlox is relatively drought-tolerant, but regular watering during dry periods will promote better flowering (Are you in a drought? Check the U.S. Drought Monitor).
Mulching: Apply a layer of mulch around the plants to help retain moisture, suppress weeds, and maintain a more consistent soil temperature.
Fertilizer: To promote flowering, fertilize in early spring with a balanced, slow-release fertilizer like Plant-tone®.
Division: Phlox subulata can be divided every 2-4 years in the early spring to rejuvenate the plant and control its size. Dig up the entire plant and separate into smaller sections, making sure each section contains both shoots and roots. Immediately replant the divided sections, and share with a neighbor or friend if you have extra!
Landscaping Ideas for Fort Hill Creeping Phlox
Spring Carpet: Combine Fort Hill with other colors of creeping phlox, like Emerald Blue, to create a colorful springtime carpet.
Lawn Replacement: Use Fort Hill creeping phlox as a no-mow, perennial ground cover on an area that is difficult to mow, such as a sunny slope or narrow strip next to a driveway.
Rock Garden: Plant Fort Hill creeping phlox in a rock garden, where it will creep and cascade over and around rock edges.
Erosion control on Slopes and Hillsides: Use a mass planting of Fort Hill creeping phlox to cover sunny slopes or hillsides, preventing soil erosion while adding a burst of color.
Edging: Use Fort Hill creeping phlox as an edging plant along walkways, sidewalks, or driveways, where it can create a bright and well-defined boundary.
Rock Wall: Plant Fort Hill creeping phlox on the top of a stone retaining wall, letting it cascade over and soften the hard edges.
Drifts and Mass Plantings: Plant large drifts or masses of Fort Hill creeping phlox for a stunning display of color. This technique is particularly effective for larger garden spaces or areas where a bold impact is desired.
Perennial Border: Plant Fort Hill creeping phlox at the front of the garden border for a tidy and well-defined edge. Arrange taller perennials behind, selecting plants with staggered blooming times to guarantee a continuous display.
Planting Companions for Fort Hill Creeping Phlox
Autumn Angel® Encore® Azalea (Rhododendron ‘Robleg’): A dwarf, compact azalea for full sun, with white flowers and dark green leaves.
Catmint (Nepeta): A spring-flowering perennial with spiky purple flowers and silvery blue leaves.
Helen von Stein Lamb’s Ears (Stachys byzantina ‘Helen von Stein’): Create a pleasing contrast of color and texture by planting this large, silvery-leaved ground cover next to creeping phlox.
Pigsqueak (Bergenia species): The large leaves of this spring-flowering perennial ground cover contrast nicely with the fine-textured foliage of creeping phlox.
Southern Wood Fern (Dryopteris ludoviciana): An adaptable fern for zones 8-10 that can handle full sun.
Why Did My Creeping Phlox Stop Blooming?
Age of the Plant: Creeping phlox tends to be more vigorous during the first few years of growth. As the plant ages, flowering may decrease. Divide and replant sections of the plant every 2-4 years to rejuvenate and encourage more blooms.
Sunlight: Lack of sunlight can result in reduced blooming. Ensure that the plant receives full sun (6+ hours of direct sunlight per day) to promote flowering. Creeping phlox will tolerate light shade, but flowering will be diminished.
Soil Conditions: Creeping phlox prefers well-draining soil. Compacted, poorly draining soil can lead to sparse flowering. Amend the soil with organic matter, like compost or Leaf-gro®, to improve drainage.
Nutrient Levels: A nutrient insufficiency can impact flowering. Fertilize creeping phlox with a balanced, slow-release fertilizer (like Plant-tone®) in early spring.
Pests and Diseases: Aphids and spider mites are occasional problems for creeping phlox, and can stress the plant and cause diminished flowering. Keep an eye out for these problems, and treat issues promptly.
Environmental Stress: Extreme weather conditions, such as drought or excessive heat, can stress the plant and affect blooming. Ensure that the phlox is adequately watered during dry periods.
Overcrowding: If creeping phlox is overcrowded or competing with other plants, it may not bloom as prolifically. Consider thinning out the plant or providing it with more space for better health.
Is Fort Hill Creeping Phlox Invasive?
Creeping phlox is not considered an invasive plant in the United States (check out the USDA’s database of Invasive and Noxious Plants). Fort Hill Creeping Phlox is a cultivar of a plant native to the Eastern United States. It does not self-seed, and will stay within its designated spot in the garden, making it a desirable choice for a controlled ground cover.
In the right conditions, such as full sun and well-draining soil, creeping phlox can thrive and spread rapidly. Creeping phlox spreads by stolons (above-ground, creeping roots), making it very easy to thin out and keep in check.