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The Daily Insight

How does tall phlox spread

Author

Victoria Simmons

Published Apr 02, 2026

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.

How fast does tall phlox spread?

Like other ground covers,creeping phlox takes a few years to reach maturity — about two years on average, according to the North Carolina State University Cooperative Extension. This means it grows an average of about an inch per month.

How do you encourage phlox to spread?

Fertilizing in the late winter or early spring will promote growth and support a more robust bloom for your creeping phlox. Feed it with a general slow-release fertilizer suitable for flowering plants, following label instructions.

Is tall phlox invasive?

Tall garden phlox is a very popular well behaved late season blooming perennial but its evil twin with the same five-petal flower arrangement is highly invasive.

How does tall phlox propagate?

Propagating Garden Phlox Propagate phlox plants by dividing them in early spring. Dig your phlox plant out of the ground and split it into smaller clumps using a sharp knife. Then replant these clumps. You can also direct sow seeds in spring as soon as the ground can be worked.

How does creeping phlox spread?

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.

How long does phlox take to spread?

Time to Maturity:2 yearsWell-drainedSpacing:15-18 inchesVarious shrubs, as it is low-growingPlanting Depth:Shallow, with top of root ball level with the groundGround coverHeight:3-8 inchesPolemoniaceaeSpread:up to 2 feetPhlox

Do Garden phlox reseed themselves?

(Garden phlox freely reseeds itself. However, most cultivars do not come from seeds. Seedlings are usually inferior plants. Large numbers can become weedy.)

Should I deadhead tall phlox?

Phlox will reseed itself so there need never be a year without these lovely flowers. Deadheading phlox blooms will prevent much of that reseeding. … Some gardeners deadhead phlox flowers to confine the spread of the plant. Since phlox is a perennial, the resulting seedlings can become weedy and often do not bloom.

Does phlox grow wild?

Wild phlox grows to roughly 2 feet tall by 2 feet wide, and sends up its summer-blooming purple-blue flowers on thin stems. Wild phlox, sometimes known as wild sweet William, grows in many types of soil, tolerates mild droughts and propagates by releasing its large supply of seeds in the fall.

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What grows well with tall Phlox?

WHERE TO PLANT GARDEN PHLOX. PERENNIAL GARDENS Garden phlox is a good companion for other summer-blooming perennials such as lilies, bee balm, rudbeckia, Shasta daisies, yarrow, clematis and daylilies. In flowerbeds, the taller cultivars provide a good backdrop for shorter plants.

Can you divide creeping phlox?

Creeping phlox clumps should be split on a cool, cloudy day. They should be lifted by pushing the tip of a shovel or garden fork into the soil 4 to 6 inches away from the plant on all sides then lifting the entire clump with the shovel tip or garden fork.

How long does tall Phlox bloom?

Count on tall garden phlox (Phlox paniculata hybrids) to provide a colorful summer display in perennial gardens, blooming as much as six weeks or more. Some cultivars begin blooming in mid-summer, others not until late August.

Can you take cuttings from tall phlox?

You can also propagate phlox by taking root cuttings in winter, before they start to send up their spring shoots. Use plants dug up from the garden or pot-grown plant. Place the pots of cuttings in a cold frame, where they’ll root and grow into new young plants by midsummer.

Can you replant creeping phlox?

During division, dig out a section of the mat of creeping phlox. When a part of the plant and its roots are exposed, sever it with a sharp spade or shovel into two or more plant sections. … Each section can be treated as a new plant, to be transplanted to a new location.

Why did my phlox stop blooming?

Some possible reasons they don’t bloom include: Not enough sun. They need at least 6 hours of full sun. Powdery mildew weakening the plant.

When should I plant creeping phlox?

Plant creeping phlox in spring. Purchase creeping phlox starter plants at a garden center or nursery. Select healthy plants that display bushy, bright green foliage. Prepare a planting spot in your garden where the plant will be exposed to full sun or partial shade.

Should phlox be cut back after blooming?

Trim back the spent flower heads and overgrown stems once the flowering cycle is complete in early summer. You can prune up until late summer, but the foliage grows lusher and the plants look less unkempt if they are pruned immediately after blooming.

Will creeping phlox keep spreading?

A perennial nature and semi-evergreen habit are important facts about creeping phlox. These plants have needle-like foliage with small starry, five-pointed flowers in red, lavender, pink, white or bluish-purple. Creeping phlox blooms in spring and produces long, spreading stems, which become woody with age.

Does phlox spread underground?

It spreads by underground stems (rhizomes) and makes a nice clump. This variety is very resistant to powdery mildew which is a concern on the taller phlox in particular.

How wide does creeping phlox spread?

Mat-forming, Phlox subulata grows only 4-6 in. tall (10-15 cm) but spreads vigorously up to 2 ft. wide (60 cm) in a beautiful flower carpet resembling moss, hence the common name of moss phlox. Its creeping stems are clothed in needle-like evergreen to semi-evergreen leaves.

Does phlox come back every year?

Phlox are easy-to-grow perennials that come back reliably every season. … Creeping Phlox blooms in mid-spring. It looks great planted with spring-blooming bulbs, like Daffodils and Tulips, or as an edging plant, or planted on slopes or stone walls where it can spill over the edge.

Does phlox flower all summer?

Growing anywhere from 10 inches to 4 feet high, tall phlox is a summer bloomer. While a few varieties can bloom into September, most tall phlox blooms in July and August. Notable exceptions are the Astoria and Intensia phlox, which bloom beautifully into late fall and even through winter in very mild climates.

How do I prune phlox?

Garden phlox (Phlox paniculata) is another plant that DiSabato-Aust enjoys pruning. “You can pinch early or cut it back by one half. Or cut it back by four to six inches when it’s in bud. It’s a really fun plant to experiment on.”

How many varieties of phlox are there?

There are over 60 species of phlox, but garden phlox is the most popular. Many produce fragrant blooms right into late summer, when other perennials have finished blooming. All cultivars of this perennial need a well-drained, rich, moist soil and have average water needs.

Does Blue Moon phlox spread?

A rhizomatous plant, ‘Blue Moon’ spreads slowly over time. We encourage planting this woodland native anywhere it can be observed, along footpaths in shade gardens or along perennial borders.

Is wild phlox invasive?

It is known that it effectively forms monocultures where it has escaped from cultivation, is a prolific seed producer, and is not kept in check by pests or diseases in North America. It is still readily available as seed commercially but is banned as an invasive in some states including Connecticut and Massachusetts.

Are sweet williams and phlox the same?

Meadow phlox, though a common garden plant, is considered rare in the wild and is on the threatened or endangered plant species list in some states.

What is the difference between moss phlox and creeping phlox?

Garden phlox (​Phlox paniculata​), hardy in USDA zones 4 through 8, has clusters of flowers atop three- to four-foot-tall stems. … Moss phlox, also known as creeping phlox and thrift (​Phlox subulata​) is a low-growing plant that is used in alpine rock gardens and to edge garden paths and flower beds.

Should Phlox be cut back in fall?

Phlox (Phlox paniculata) Phlox is prone to powdery mildew, and even the resistant varieties can become infected in bad weather. 9 If so, prune and destroy all foliage and stems in the fall. Even if the plant is healthy, it will benefit from some thinning to increase airflow and prevent disease.

Should I mulch around creeping phlox?

Creeping phlox( Phlox stolonifera )is an excellent ground cover. Yes, I recommend using mulch the first season when establishing a groundcover. It will help to suppress the weeds while the ground cover fills in.