How to Grow Phlox Drummondii

Phlox drummondii flowers in bloom

Sucharas Wongpeth / Getty Images

 

There are more than 60 different species of phlox, but the phlox drummondii, commonly known as the annual phlox or the Drummond phlox is a Texas native that comes in a variety of bright, showy colors.

This plant was discovered by Thomas Drummond in the early 1800s in its home state of Texas, but quickly its fame quickly grew in England and other parts of Europe.

Today the annual phlox is equally at home in gardens and roadsides. The trumpet-shaped blooms come in shades of red, pink, purple, and white and often feature a lighter center, known as the eye. 

Botanical Name Phlox drummondii
Common Name Annual Phlox, Drummond Phlox, Pride-of-Texas, Texas Pride
Plant Type Annual
Mature Size 6 to 20 inches tall
Sun Exposure Full to part sun
Soil Type Loose, well-draining
Soil pH Acidic to neutral
Bloom Time Spring, summer
Flower Color Red, pink, purple, white
Hardiness Zones 2 to 11
Native Area Texas
Phlox drummondii bloom up close
Littlewitchz / Getty Images

How to Grow Phlox Drummondii

Phlox drummondii is an abundant wildflower in its native land of Texas—proving that it grows well even with limited time and attention.

To make the most of this blooming beauty in your garden, be sure to plant in an area with sufficient sunlight and provide an all-purpose fertilizer for the most abundant flush of flowers.

Deadhead the annual phlox regularly to encourage continued flower production and minimize self-seeding. Some gardeners, however, let them self-seed and successfully avoid needing to replant this annual flower year after year.

Light

Like many other flowering plants, annual phlox needs some sunshine in order to produce the colorful blooms it has become known for. It does best when planted in garden positions that get at least six hours of sun each day during the growing season.

If you live in a region with extremely hot and sunny weather, they may actually do better in partial shade where they’ll be protected from intense heat.

Soil

Often found in grasslands and meadows, the phlox drummondii can adapt to a variety of soil conditions—as long as the ground is well-draining. The ideal scenario is loose, sandy soil with rich nutrients, but these plants can grow in less-than-ideal conditions. Soil pH levels should be slightly acidic to be neutral (6.0 to 7.0) for this plant's well-being.

Water

Phlox drummondii appreciate consistently moist conditions during the growing season. If you live in an area of low rainfall, they will need frequent watering throughout the summer months.

Temperature and Humidity

Native to the hot, dry climate of the southeastern United States, the annual phlox loves warm weather and plenty of sun.

Climates with high humidity can lead to powdery mildew problems on the leaves of the annual phlox. Watering from the roots and minimizing splashing on the foliage of the plant can assist in preventing this problem.

Fertilizer

To put on a show each summer, the annual drummondii will need sufficient soil nutrients to support lush foliage and abundant flowering. For this reason, these plants do best planted in fertile soil.

If your soil is lacking in nutrients, then it will be necessary to apply fertilizer during the growing season to feed the plants. However, keep in mind that too much nitrogen can lead to leggy growth and poor flowering performance.

If you’re unsure of your soil’s nitrogen levels, get a soil sample analyzed and make fertilizer decisions based on the NPK (nitrogen, phosphorous, potassium) of your dirt.

In general, flowering plants do well with a fertilizer formula with a higher ratio of potassium when compared to nitrogen and phosphorous. Also skip foliar fertilizers (applied to the leaves), since the sticky, hairy leaves of the annual phlox will hinder nutrient absorption. 

Propagating Phlox Drummondii

Phlox drummondii is most commonly propagated by seed. The seeds for these plants are widely available commercially, but you can also collect them from spent blossoms.

Look for the small seed pods at the base of wilted blooms. When dry, the pods will easily split open to reveal the small, brown seeds inside.

Plant annual phlox seeds in the garden a couple of weeks before the last expected spring frost. Or, if you want to begin growing your seedlings even sooner, you can start the seeds in a container and transplant them outdoors at a later time.

Varieties of Phlox Drummondii

  • Phlox drummondii ‘Phloxy Lady’: This cultivar is intended to bloom longer than conventional annual drumondii. It features blooms in vibrant shades of red, pink, and purple, along with white. It does best in USDA zones 10 and 11.
  • Phlox drummondii ‘Giselle Hot Pink: Available in a number of shades, including a hot pink variety. These phlox plants demonstrate even greater tolerance to heat and are a great option for gardens or containers where you want a pop of intense, dynamic color.
  • Phlox drummondii ‘Pop Stars: The most unique thing about this variety of annual phlox is its star-shaped blossoms.
Phlox drummondii 'Pop Stars' variety
Phlox drummondii 'Pop Stars' variety  Mayerberg / Getty Images

Toxicity of Phlox Drummondii

Phlox drummondii is not reported to be toxic to people or animals. While another member of the phlox family, the perennial phlox, frequently appears on the list of edible flowers, this variety is less commonly consumed. Still, you won’t need to worry about accidental (or intentional) ingestion of this flower.

Being Grown in Containers

Annual phlox are great candidates for being grown in containers. With their mounding growth and bright blooms, these plants are a cheery option for window boxes, hanging planters, or container gardens.

When growing phlox in containers, keep in mind that these plants have a one to two foot spread and plant them accordingly.

You should also take steps to ensure the container has sufficient drainage. Without this, the roots can become soggy leading to rot problems or poor crown growth.

While phlox planted in the ground don’t always need fertilizer for good growth, you may need to supplement your container kept phlox with an all-purpose fertilizer during the growing season for the best blooms.