Growing Creeping Phlox
Growing Creeping Phlox
Creeping phlox (Phlox subulata), also called moss pink and thrift, is a hardy perennial native to North America. Perhaps that's why it's so easy to grow for many gardeners - it seems to thrive in many different types of soils, and as long as it gets full sunshine and reasonable moisture, it continues to bloom each spring and spread rapidly.
Selection and Planting Location
Creeping phlox is a low-growing, evergreen perennial. It only gets about six inches tall, but it can spread out rapidly - hence its use as a ground cover. It is hardy in garden zones 3 to 9, making it suitable for most (but not all) USA garden locations. It's also quite popular in the UK, Japan and countries with similar growing conditions.
Choose a sunny location for your creeping phlox plants because they do need full sun, which is defined as six or more hours daily of bright, direct sunshine. According to the North Carolina Extension office, creeping phlox tolerates most soil types. I've found it tolerates clay fairly well, as well as sandy loam.
If your soil is very poor, amend it with compost when planting creeping phlox.
One thing that I found out from experience is that you can start with very small plants. They grow and spread rapidly, so small plants won't remain small for long! This makes creeping phlox and economical choice if you have a large area to cover, such as a slope. They are good for erosion control, borders, and butterfly garden borders.
To plant creeping phlox, find a sunny location. Dig the planting hole twice as wide and as deep as the pot the phlox is currently growing in. Gently turn the pot on its side and tap the sides and bottom of the pot with your hand to loosen the soil. Pull on the stems and leaves, not the crown of the plant. If a stem or leaf breaks, it can grow back, but tugging at the main crown and breaking it can damage your plants. Remove the plant from its pot.
Add an inch of compost to the bottom of the planting hole and place the plant's roots and soil from the original pot inside the hole, making sure that the crown is at surface level. Scoop the dirt back into the hole, tamping it down with your hand. Add mulch and water well. Provide supplemental water if it doesn't rain for several days. While creeping phlox is drought-tolerant, it needs time to establish strong roots first.
- Leave at least 1 foot of space between plants. When you're planting creeping phlox, leave plenty of space between the plants. It may seem as if the instructions on the back of the plant tag call for you to leave too much space between the plants, and the urge to cover up those bare spots between the plants can be overwhelming. Resist the urge! Creeping phlox spreads, and spreads and spreads...and that empty space will soon be filled by its interesting evergreen foliage.
- Fill gaps with annuals: If you must fill in the gaps, plant annual flowers the first year to tide you over, and mulch the area well.
Seed Starting and Division
You can plant creeping phlox seeds or plants purchased from a nursery or garden center. Once your plants are strong and vigorous, you can divide existing patches of creeping phlox once every 3 to 5 years.
Growing Creeping Phlox from Seeds
If you purchase creeping phlox seeds, refer to the back of the seed package for instructions on the right time to plant your seeds. Generally, creeping phlox seeds are planted outdoors after all danger of frost is past. Till the soil and work in some good well-rotted compost. Sprinkle seeds about 6 inches apart. Water daily until seeds emerge. Thin seedlings to leave a one foot space between creeping phlox and continue watering until the plants are several inches tall.
Dividing Creeping Phlox
Creeping phlox can be divided to create new plants. Wait until the plant is at least 3 years old. By that time, it has an established root system and is probably bigger than you want it to be!
- Choose a new spot for the division.
- Use a sharp spade. Dig up the original plant.
- Use clean gardening shears or your spade and slice the plant in half, making sure there are roots on each half.
- Replant the original plant. Add compost to the planting hole.
- Plant the division in a new hole.
- Water both well.
Pruning Creeping Phlox
Yes, you can prune creeping phlox! As you can see from my pictures, I grow creeping phlox along two edges in the garden. The one with the slates is my front walkway, and the creeping phlox will rapidly overcome the sidewalk if we let it. The one in the backyard tends to overgrow the garden bed and spill onto the grass, so that one requires pruning, too.
To prune creeping phlox, make sure that you have clean, sharp garden pruners. Wait until late spring after the plants have finished blooming. Trim off any dead branches and trim the plants to the size you wish them to be.
Creeping phlox has several wonderful uses in the landscape.
Creeping phlox is an excellent butterfly gardening plant. Use it as a borer or edging and plant other butterfly plants nearby.
Native Plant Gardens
Creeping phlox is native to North America. You can incorporate it into a native perennial garden scheme along with daylilies, echinacea and others.
I love growing creeping phlox along a rocky wall. Just make sure that if you plant is in your rock garden, you include plenty of soil among the rocks so that it can establish good roots. The creeping phlox spills over the rocks like a colorful waterfall in the spring.
Borders and Edging
Creeping phlox makes an excellent border or edging plant. It will not grow very tall, and it will spread out along the border to demarcate your garden beds quite nicely.
Lastly, you can grow creeping phlox on a slope or hillside as part of a soil erosion control project. The roots help hold soil in place while providing a colorful carper in the springtime on the slope.
With its many uses, creeping phlox is a great addition to many gardens. It's inexpensive to grow from seeds or to purchase as plants and available through mail order as well as at garden centers nationwide.
© 2013 Jeanne Grunert