Phlox Info and Care

Phlox Info and Care

Native to Eastern North America, Phlox is a genus that encompasses over 67 varieties of perennial and annual plants belonging to the family Polemoniaceae.

Its name comes from the eponymous word of Greek origin, which loosely translates to flame, referencing some varieties’ intense and striking flower colors.

Phlox is an herbaceous plant, and most members of its family are disease and pest hardy, with some exceptions such as Garden Phlox. Some types of Phlox are creepers, also known as wild ground phlox, that form soft, short flower islands.

They usually range from 2 feet to 4 feet in height and 2 to 3 feet in width, while years of breeding have resulted in several smaller garden-worthy cultivars.

Phlox Info and Care

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Phlox Flower

These tall and eye-catching ornamental plants with clusters of minute flowers are a perfect addition to any garden, and they also make excellent cut flowers.

Some of its varieties are lightly fragrant and come in a range of colors and color combinations, including pink, purple, red, and white.

Each flower in the cluster grows 1 inch in diameter and comprises five or more rounded petals. Usually, the flower’s heart is a different color from the color of the petals. However, the annual Phlox drummondii has very striking two-tone serrated petals.

How to Grow Phlox

Water Requirements

These plants do not enjoy drought, so make sure to water your Phlox regularly.

They should receive around 1 inch of water per week in spring and summer’s growing seasons.

To keep your plant’s foliage healthy and shiny, water Phlox at the root zone below its foliage and provide it with all-day freshness in the morning. These gorgeous plants thrive in moist soil, but be careful not to overwater them! 

Soil Requirements For Phlox Plants

Phlox thrives in relatively moist soil rich in nutrients. However, they do not respond well to dry and sandy soil, so avoid such substrates.

If your natural garden soil is dry, you may improve it with organic matter such as organic compost to increase its consistency and fertility.

Temperature Requirements

Like most outdoor plants, Phlox adapts well to changing external conditions.

For example, perennial Phlox overwinters without damage in climate zone 4 to 8. And in climate zone 3, during the winter months, it is useful if you cover the plant’s roots with mulch to prevent freezing roots.

Light Requirements

Although most of these plants enjoy the full sun, they can thrive in a spot with a few hours of shade. Still, the phlox flower needs at least 6-7 hours of direct sunlight to remain compact and abundant. A lot of shade means a leggy plant with few flowers!


The best fertilizer for your Phlox is granular slow-release all-purpose fertilizer with 10:10:10 NPK, which you can apply around the base of the plant in early spring when forming flower beds.

If your garden soil is poor, you may add a couple of inches of compost to provide additional nutrients. On the other hand, be careful with fertilizer as over-fertilizing can burn Phlox’s roots resulting in plant decay.

Tall Phlox Mix Value Bag-6 Roots/Plant Starts
  • One of the most loved and known of the summer-blooming flower, the tall garden phlox is a staple in many perennial gardens.
  • A second re-blooming can often be experienced in fall if deadheading is performed.
  • Six roots, with a mix of Blue Boy Tall Phlox (Blue), David Tall Phlox (White), Peppermint Twist (White/Pink), Star Fire Tall (Pink.)

Overwinter Care

While most perennial Phlox plants will grow back in the following spring, when the plant enters its dormant phase in fall, cut the plant’s foliage to ground level.

If you do not, it will turn black during the first months of fall and winter. To protect its root from low temperatures, apply a generous layer of dead leaf mulch.


Phlox is a hardy perennial that is easy to propagate. You can choose one of the following two methods.

Phlox Plant Dividing

You can propagate the existing plant by separating the lateral shoots.

In early spring, when the new growing season begins, dig out the root ball from the ground and separate the new plants that grow on the same root, ensuring that each new shoot has a part of the root.

Phlox has a horizontally branched root, so you don’t need to bury the new plants deep in the ground.

Growing Phlox From Seeds

Another way of propagation is by sowing seeds.

  • For this step, choose a quality starter soil and a sterilized plastic container with at least one drainage hole.
  • After filling the container with the nutrient-rich potting mix, spread the tiny seeds and cover them with a thin layer of soil.
  • Moist the soil with a generous amount of water, using a spraying bottle for even distribution.
  • The next step is to cover it with a plastic lid and place it in a warm, bright location.

The best time to sow your Phlox is approximately six to eight weeks before the last frost.

You can also sow Phlox seed directly on the flower bed in the second half of April when the danger of late frosts passes. When the seedlings emerge and strengthen, you can replant them at a 5 to 10 inches distance to have enough room to grow. Phlox has a horizontally branched root, so you don’t need to bury it deep in the ground.

Leave some space around the flowers to facilitate their flower spread when planting them.

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