Phlox, phabulous phlox, a staple in the southern garden. Garden phlox is a traditional favorite for borders. Its mounded flower clusters come in many colors (white, pink, red, orange, purple, and blue). It combines well with many other favorite summer bloomers and is one of the most versatile and colorful groups of flowering perennials, ranging from the low, spreading moss phlox to the familiar garden phlox. The tall, eye-catching perennials are ideal for sunny borders. In addition, the large clusters of flowers bloom for several weeks in summer and make excellent cut flowers. Growing hardy garden phlox is simple and so is its general care.
There are several species of perennial phlox for garden culture. Three of the most common phlox are Carolina phlox (Phlox Carolina), garden phlox (P. paniculata), and creeping phlox (Phlox subulata). My personal favorite phlox is Carolina phlox. It is sterile and therefore does not set viable seed and self-sow. This saves them from the "revision" problem that garden phlox face. Self-sowing usually results in seedlings that are not always the same as the parents and can add to garden chores of plucking out the less desirable plants that over-crowd beds. These seedlings are usually tougher than the cultivated plants with the result that they crowd out the original variety. You can diligently remove the faded blossoms before the seeds ripen.
The species of phlox most commonly found in nurseries and garden centers is garden phlox (P.paniculata) also called summer phlox, is a sun-loving perennial with a long flowering season. Large clusters of flowers, called panicles, sit atop stems that grow 3 to 4 feet tall. This native American wildflower thrives in zones 4-9. It blooms spring, summer and into fall, depending on the variety. It will grow in full sun to full shade (also depending on the variety). Phlox can (and should be!) the centerpiece of a color themed southern garden. Plant this beauty alongside lower growing perennials such as mounding coreopsis, oxalis, or pinks so it gets good air circulation and steals the show!
Plant garden phlox in full sun or partial shade and in most cases in moist, humus enriched soil that is well draining. Give the plants plenty of room for garden phlox is especially susceptible to powdery mildew fungus and needs a location with good air circulation. Fertilize with a shovelful of compost for each plant or a light application of 10-10-10 fertilizer at planting time and again just before the flowers open. If you fertilize once more after the flowers fade, you may get another flush of flowers.
Propagate phlox by sowing seeds in midsummer, by dividing established clumps just after flowering, or by taking firm, leafy stem cuttings in summer. I have better luck dividing clumps just after flowering. All phlox should be divided every 3-5 years.
The third species of phlox (Phlox subulata) or creeping phlox produces a colorful carpet of soft pastel hues and is perhaps easiest of phlox to grow and care for. It requires little expert knowledge on how to plant and tend. It can be planted over a rockery or in tough soil conditions and provides an almost carefree ground cover that will cascade between pavers and over rocky outcrops.
Creeping phlox has an easygoing nature and thrives in a variety of conditions. Almost any soil is suitable for growing creeping phlox as long as it is in full sun to partial shade. For best results, plant in a sunny location where soils are moist but well drained. Dig in some organic soil amendments to enrich the soil and water the plant until it is established. Plant creeping phlox at soil level and avoid burying the stem.
These phlox have needle-like foliage with small starry, five-pointed flowers in red, lavender, pink, white or bluish-purple and produce long, spreading stems that become woody with age. These thicker growths cease to produce flowers with age and should be cut out of the plant to encourage the newer, softer stems that do bloom. In addition, the plant has a moderate growth rate and can get 4 to 6 inches high with a 2-foot spread.
Make phabulous phlox a staple in your garden and you will enjoy this colorful addition for years to come!
• Carolyn McMillan is a Virginia Master Gardener with the Virginia Cooperative Extension Prince George County Office. Virginia Master Gardeners are volunteer educators who work within their communities to encourage and promote environmentally sound horticulture practices through sustainable landscape management education and training. Virginia Master Gardeners bring the resources of Virginia’s land-universities, Virginia Tech and Virginia State University to the people of the commonwealth.