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How to Grow Phlox: Planting & Care Guide for Phlox Flowers

white phlox flowers
Photo Credit
Pixabay
Botanical Name
Phlox
Plant Type
Flowers
Sun Exposure
Full Sun
Part Sun
Shade
Bloom Time
Spring
Summer
Flower Color
Blue
Pink
Purple
Red
White
Hardiness Zone
2
3
4
5
6
7
8
9
Special Features
Attracts Butterflies
Attracts Songbirds

From Ground Covers to Garden Giants: Meet the Many Faces of Phlox

Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Looking to add a pop of color that butterflies love but deer won’t touch? Meet phlox—your new favorite flowering perennial. Whether it’s the candy-colored carpet of creeping phlox in early spring or the fragrant, tall blooms of garden phlox in summer, this versatile bloomer brings beauty to beds, borders, and everything in between. Ready to grow a garden showstopper that doesn’t mind a little shade or sun? Let’s dig into how to plant, grow, and care for phlox!

About Phlox

“Phlox is a genus with a great diversity in growth form, with a height varying between 3 to 6 inches for Phlox subulata to 5 feet tall for Phlox paniculata. They may grow in a low, mounding form, a spreading woodland phlox or tall, upright phlox,” explains the North Carolina Cooperative Extension.

These perennials sport copious star-shaped, colorful flowers from spring through summer, depending on the variety. Because there are so many types (many of which are native to North America), you can find a phlox for almost any garden. Truly, their versatility can’t be overstated. 

  • Low-growing Creeping Phlox works great as ground cover in sunny yards.
  • Ankle-high Woodland Phlox is perfect for dappled, shady beds.
  • Medium-height Garden Phlox is often the ‘backbone’ of the perennial garden, providing a layer of color midway through the garden and filling in gaps.
  • Tall Garden Phlox are excellent as a colorful backdrop with large flower clusters, and they are often fragrant. 

Bees, butterflies, and pollinators also adore Phlox. And fortunately, phlox is deer-resistant, as deer do NOT like smelly flowers!

Read Next

Planting

Because there are so many different types of phlox, sunlight requirements vary. Tall garden phlox do best in full sun, while woodland species thrive in partial shade. (See Recommended Varieties, below, for more information!)

In general, phlox prefer soil that is nutrient rich and evenly moist. They do not like to sit in wet soil, however. Use a garden fork or tiller to prepare your garden bed prior to planting. Loosen the soil to about 12 to 15 inches deep, then mix in a 2- to 4-inch layer of compost to improve soil consistency and fertility.

When to Plant Phlox

How to Plant Phlox

  • It is easier to grow phlox from cuttings/transplants than from seeds, although established plants will readily spread by seed in the garden.
  • Space plants according to their mature size.
  • If you are transplanting a plant from a pot, dig a hole about twice the size of the pot’s diameter and place the plant so that the top of the root ball is even with the soil’s surface. Fill in around the root ball, and remember to water it thoroughly.

white, pink, and purple Phlox flowers

Growing

  • If you receive less than 1 inch of rain a week, remember to regularly water your plants throughout the summer.
  • Each spring, put a thin layer of compost and a 2-inch layer of mulch around the plants to help keep the soil moist and control weeds.
  • Remember to remove the dead/faded flowers so that your plants can rebloom. Try out the Chelsea Chop!
  • If you have tall phlox, cut the stems back to about 1 to 2 inches above the soil after the first killing frost in the fall. (See local frost dates.) Divide tall garden phlox every 2 to 3 years to ensure healthy and disease-free plants.

Types

You just can’t go wrong with phlox! Here are some of the best species and varieties to try:

Low-Growing Phlox

  • Creeping phlox or moss phlox (Phlox subulata) is a low-growing species that works excellently as a ground cover. It spreads slowly, growing in mounds that get 4–6 inches thick. The whole plant turns into a carpet of color in spring, when flowers cover every square inch of foliage. This phlox is particularly stunning when allowed to drape over a rock wall—imagine a waterfall of color! Creeping phlox grows best in well-draining soil and partial to full sun.
    • ‘Candy Stripe’ is a popular variety with pink-and-white–striped flowers.
    • ‘Emerald Blue’ produces a sea of lilac-blue flowers (perfect for that waterfall of color!).
Creeping phlox
Creeping phlox (P. subulata) has needle-shaped leaves and produces a carpet of flowers. 
  • P. stolonifera, which also goes by the common names creeping phlox and moss phlox, is similar to P. subulata in name only. The main differences between it and P. subulata are that its leaves are oval-shaped (rather than needle-shaped), and its flowers are produced on stems that rise 6–10 inches above the foliage (rather than directly on the foliage). It prefers a shadier growing site with rich, evenly moist soil.
    • ‘Sherwood Purple’ is a delicate little phlox with purplish-pink flowers.
  • Woodland phlox or blue phlox (P. divaricata) is another low-growing species. As its two common names suggest, it prefers partial to full shade and moist, rich soils and produces bluish flowers in early spring. Like P. stolonifera, its flowers bloom on stems that rise about a foot or so above the creeping foliage.
    • ‘Chattahoochee’ and ‘Blue Moon’ are two great varieties with beautiful blue-to-violet flowers.
Blue phlox. Phlox divaricata.
Blue phlox. Phlox divaricata. Credit: L Lauzuma

Medium-Height Phlox

  • Annual phlox or Drummond’s phlox (P. drummondii) grows as an annual rather than a perennial, unlike most other phlox species. Annual phlox rarely grows taller than 2 feet in height. Most varieties are not very heat tolerant, but in warmer regions, you may find the heat-tolerant varieties for sale. Plant in well-draining soil in a site that gets partial sun and doesn’t stay too wet.

Tall Phlox

  • Garden phlox or summer phlox (P. paniculata) is the tallest phlox in cultivation and is probably the species that most folks have in their gardens. It grows in clumps that reach between 3 and 5 feet in height and produces panicles of flowers in mid- to late summer. Though tolerant of most lighting, it grows and flowers best in partial to full sun. It has a reputation for being very susceptible to powdery mildew, but resistant varieties are available.
    • ‘David’ has bright white flowers and is resistant to powdery mildew.
    • ‘Jeana’, another mildew-resistant variety, produces panicles of petite purplish flowers—similar in appearance to a butterfly bush.

Other Phlox

The phlox listed above are just a few of the many species out there. Others of interest to gardeners may be Carolina phlox (P. carolina), meadow phlox or spotted phlox (P. maculata), and sand phlox (P. bifida).

Gardening Products

Pests/Diseases

  • Powdery mildew is common; keep proper air circulation in mind when spacing out plants and avoid getting excess water on the foliage. Cutting back stems after flowering can also help to reduce the spread of powdery mildew, as can choosing mildew-resistant varieties.
  • Stem canker
  • Rust
  • Southern blight
  • Stem nematodes
  • Leaf spots
  • Leaf miners
  • Caterpillars

Wit and Wisdom

  • April’s full Moon has traditionally been called the “Full Pink Moon” because it heralded the appearance of the “moss pink,” or wild ground phlox—one of the first spring flowers.
  • Medium and tall phlox are good companions for summer perennials such as lilies, bee balm, rudbeckia, Shasta daisies, yarrow, and clematis.

Flowers
About The Author
Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the website companion of The Old Farmer's Almanac. She covers gardening, plants, pest control, soil composition, seasonal and moon c...
Read More from Catherine Boeckmann

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Comments

<span>Karen Hicks</span> Wed, 08/28/2013 - 16:14
I spent the first part of the summer pulling out phlox from around my house and picking the little green seeds off my cats. Is all phlox like this? It's pretty but the seeds are a pain in the butt.
<a title="View user profile." href="/author/editors">The Editors</a> Sat, 09/07/2013 - 10:09

To avoid this issue, just deadhead your phlox before they go to seed. This is good practice (not just because of your cat); the little seedlings tend to crowd out the mother plant over time.

 <span>Igor</span> Fri, 08/23/2013 - 19:20
may phlox be annual?
<span>Suzen</span> Fri, 05/02/2014 - 09:21
there is an annual phlox one can purchase often in multi colored mix seed packs. They grow to about 12-18" tall and if trimmed of flowers going to seed will continue flowering all summer.
<a title="View user profile." href="/author/editors">The Editors</a> Sat, 08/24/2013 - 06:20

Phlox are perennials.

 <span>Jackie Holloway</span> Fri, 08/16/2013 - 13:32
Flower don't bloom had plant for over3years did fertalizer like other suggestion and only one flower help please
<a title="View user profile." href="/author/editors">The Editors</a> Mon, 08/19/2013 - 07:22

Is your phlox getting enough sunlight? It needs 4 to 6 hours of DIRECT sunlight at minimum. As you mentioned, you can also fertilize. Applying Miracle-Gro one time per month should be ample. If your phlox does not bloom next year, you may want to rip it out and begin anew.

 <span>Holly Crosgrey</span> Tue, 07/30/2013 - 14:47
Hi, when you say remove the dead flowers so it will re-bloom, do you mean just pick off the dead flowers or do I cut the small flower stems that the dead flowers are on.
<a title="View user profile." href="/author/editors">The Editors</a> Mon, 08/05/2013 - 07:42

Deadhead the dead bloom a quarter-inch above the next bud. You can use a pair of snip with sharp scissors or hand pruners. 

 <span>Kelly Love</span> Tue, 07/09/2013 - 12:01
I live in MN and planted 3 creeping phlox this spring to go over a retaining wall. They aren't blooming at all and they aren't creeping. What should I do?