How to Grow Perennial Phlox Plants

Gardener's HQ Guide to Growing Phlox

This page is dedicated to how to grow the perennial varieties of Phlox. Information on how to grow annual phlox here.

The timing of blooming of Perennial phlox's depends on the species. It ranges from spring through to the early months of autumn.

Phlox can be upright or prostrate in nature. They carry masses of flowers thatare often star shaped. Phlox blooms in many colors depending on the species; these include white, blue, pink, and purple flowers.

Starfire Phlox by Daryl_mitchel; creative commons.

There size makes them very versatile ,and they may be used in many parts of the garden including rock gardens, borders, and edging, wildflower gardens or anywhere really.

Common species of phlox include Moss pink, David, and Garden phlox.

Commonly Grown Phlox Species Photographs and Plant Identification

Phlox paniculata

Phlox paniculata (Garden Phlox / perennial Phlox / Summer Phlox / Fall Phlox), photograph by Sonnia hill; CC.

Phlox subulata

Phlox subulata (Moss phlox / Creeping phlox Candy Stripes cultivar / Moss Pink), photograph by Babij; CC.

Phlox divaricata

Phlox divaricata (Wild Blue Phlox / Woodland Phlox / Wild Sweet William), picture by Erutuon; CC.

How to Grow Perennial Phlox in the Garden

When growing perennial phlox from seeds it is best to do so outdoors. Sow the seeds into flats, and lightly cover the seeds in the autumn.

The flats should then be sunk into the ground in a fully shaded part of the garden, and covered with glass.

Be sure to check on them regularly to make sure the soil remains moist. It should take about 4 to 7 weeks for the seeds to germinate.

The seedlings can then be transplanted the following spring (or in autumn if the perennial phlox seeds are slow to germinate).

They should be spaced at about 15 cm (6 inches - small species) to 60 cm (2 feet - large varieties) apart; they require good circulation of air to prevent mold.

Phlox are able to grow in both partially shaded and sunny areas, and ideally should have a moist soil that is rich in organic matter and of pH 6.5 to 7.5.

Caring for Perennial Phlox

It is important to keep perennial phlox plants moist, so water regularly, however try to ensure that you water the soil and not the leaves as they are susceptible to mold.

Once blooming occurs deadhead dying flowers to prolong the season. Once the season is over cut back hard to tidy the plant.

When spring arrives cut back hard to thin the phlox, just leave 4 stalks.

If you require more plants they can be propagated by division (autumn) or take cuttings (start of spring).

Common Questions

How many members does the Perennial Phlox genus contain?

The term "Perennial Phlox" usually refers to several species within the larger Phlox genus, which currently is listed as having 67 species. Prominent perennial species include Phlox paniculata and Phlox subulata.

Do Perennial Phlox members make a good garden or landscaping plant?

Yes, Perennial Phlox are fantastic garden plants. With their clusters of vibrant flowers and ability to attract butterflies, they're excellent for borders, rock gardens, or as ground cover.

Which Perennial Phlox species are most frequently grown by gardeners?

The most commonly grown perennial Phlox are Phlox paniculata (Garden Phlox) and Phlox subulata (Creeping Phlox), both known for their abundant, bright flowers.

Are Perennial Phlox plants fragrant?

Yes, many species of Perennial Phlox, especially Phlox paniculata, are known for their sweet and sometimes spicy fragrances.

What is the perfect location to grow Perennial Phlox?

Perennial Phlox prefer full sun to light shade and well-drained soil. Phlox subulata can tolerate poor soil conditions and is ideal for rock gardens.

Is Perennial Phlox invasive in the USA, if so in which states?

Currently, Perennial Phlox species like Phlox paniculata and Phlox subulata are not considered invasive in the USA and are widely grown in gardens.

How do I remove Perennial Phlox plants from my garden?

To remove Perennial Phlox, dig up the plant ensuring to remove all roots. Phlox subulata can spread, so be sure to remove any trailing stems as well.

Summary

Phlox paniculata, commonly known as Garden phlox or Perennial phlox, is a favorite of many gardeners for its long blooming period and charming clusters of fragrant flowers. Native to North America, it is an excellent choice for perennial borders.

Perennial phlox thrives in full sun to partial shade, in rich, well-drained soil. It's generally planted in early spring. Notable species include Phlox paniculata 'David' known for its white flowers and disease resistance, and Phlox paniculata 'Blue Paradise' enjoyed for its unique blue blooms.

I hope that you enjoyed this guide on how to grow Perennial Phlox plants. You may also enjoy the following Polemoniaceae family growing guides: How to grow Cobaea, Thimble Flower, and Polemonium plants.