The Hampton Gardener: Colorful carpets of phlox

0
35

For nearly a month I marveled at the pink carpet spanning the steep hill of our neighbor’s front yard. It began as a mat that went from straw brown to emerald green in March then, during the second week in April, the slope took on an ever so slight pinkish hue.

Days later, the hillside was covered in small 1-inch pink flowers that kept on blooming through 80-degree days and 25-degree nights.

Undaunted, the phlox bloomed on, ceasing to flower only some six weeks later when it faded back to green.

This particular species of phlox is known as subulata (Phlox

subulata) and it has common names like moss pinks and creeping phlox. It is only one of dozens of plants in this widely spread genus that includes annuals, biennials and perennials that grow from full sun to fairly deep shade, but because of my own particular bias we’ll stick to the perennial varieties this week. Even so, the choices are wide ranging, from the ground hugging creepers to the tall garden phlox that can reach 4 feet in height with scents that can rival many summer flowers.

Moss phlox forms dense, carpet-like mats. Plants are generally 4 to 6 inches tall, though some varieties, like ‘Red Wings,’ are wiry loose growing to 15 inches long. Phlox foliage is narrow, stiff and needle-like in appearance. Flower colors include white, pink, red, blue, and purple and there are a couple of bi-colors. Excellent varieties include ‘Emerald Blue,’ ‘Emerald Pink,’ ‘Scarlet Flame’ and ‘White Delight.’

Moss phlox is easy to grow. It performs best in sunny areas and well-drained soils, especially on a slope. Shearing the plants back right after flowering promotes dense growth and occasionally some rebloom. If they are not sheared they can become leggy and over a period of 5 to 7 years, they may become sloppy looking. The annual ritual of shearing keeps the plants tight and always promotes heavy flowering.

Deer and rabbits will help with this task and a spray of repellent in later winter will keep these feasters from snipping off the blooms that formed the previous summer and fall.

Moss phlox is useful for edging beds and as a ground cover for sunny slopes though it will tolerate some light shade. It also looks nice planted among rocks or atop a wall. It is virtually insect- and disease-free and it will appreciate a single light application of an organic fertilizer in late March.

Propagation is by rooting cut stems of about 2 to 3 inches in a box of wet sand kept moist and in the shade. Rooting in June will take about four weeks, then the individual pieces can be planted out. The same variety planted in different exposures can often flower several weeks apart with southern facing plants flowering in early April while northern exposed plants may flower two to three weeks later.

Another low-growing phlox is Phlox

stolonifera

. Its common name is creeping phlox. Plants are 6 to 12 inches tall and bloom slightly later in spring than P.

subulata

. Creeping phlox does best in moist, well-drained soils in partial shade, so it can make a wonderful woodland underplanting where it can naturalize nicely. Excellent varieties include ‘Blue Ridge,’ ‘Pink Ridge,’ ‘Bruce’s White’ or ‘Ariane’ (white with a conspicuous yellow eye), and ‘Sherwood Purple’ (purplish-blue). Creeping phlox is an excellent ground cover for partial shade. It also does well as an edging plant. This plant is easily divided and transplanted in early spring or right after flowering.

Another native phlox species is woodland phlox (Phlox

divaricata

). It is commonly found in moist, partially shaded woodland sites. It produces loose clusters of showy blue to violet flowers in spring and the plants are typically 12 to 15 inches tall. Woodland phlox is an excellent plant for, of all things, woodland gardens. It can also be used in the front of the perennial bed or planted in clumps among other low-growing, shade tolerant perennials. ‘Fuller’s White’ is an excellent variety. It is slightly smaller (8 to 12 inches) and is covered with white flowers in spring. ‘Chattahoochee’ (a cross between P.

divaricata

var. laphamii and P.

pilosa

) has lavender-blue flowers with dark purple centers. These species are propagated by tip cuttings taken in mid-summer.

One of the most widely grown phlox species is garden phlox or tall phlox (Phlox p

aniculata

). Garden phlox is a clump-forming, upright plant that produces large, showy flower clusters in mid to late summer. Plants are generally 2 to 4 feet tall. While the species itself is seldom grown in gardens, there are numerous varieties available. Gardeners can choose from white, pink, red, blue and purple flowering varieties as well as some with “eye” spots and bicolors. Unfortunately, most varieties of garden phlox are susceptible to powdery mildew, which produces a grayish-white coating on the stems and leaves of infected plants. Infected leaves turn yellow and eventually dry up and turn brown. Mildew infected plants become ugly eyesores in perennial gardens. As a result, the popularity of garden phlox has its ups and downs, but there are many mildew-resistant varieties and there are both organic and chemical strategies for controlling mildew.

While good cultural practices, such as adequate plant spacing and thinning the stems to reduce crowding and increase air circulation, can reduce the severity of powdery mildew, gardeners wishing to plant garden phlox should select the mildew-resistant varieties, including ‘David’ (white flowers) and ‘Eva Cullum’ (flowers are pink with red eyes), though you can find many more that claim to be mildew-resistant or tolerant.

Garden phlox grows best in moist, fertile, well-drained soils in partial to full sun. Plants often need to be watered during hot, dry periods and they may need some staking.

Garden phlox make excellent cuts that are beautiful and sweet smelling when brought indoors during the summer months. If the lower leaves are spotted or mildewed they can simply be stripped off. The plants form clumps that can be divided in the fall or early spring usually quartering each 3-year-old clump. A cool trick to get lots of these plants is to drive a bulb planter straight through the crown in late fall. Come back in early spring and you’ll have dozens of small plants that can be lifted, transplanted and flowering the following year.

Spotted phlox (Phlox

maculata

) is similar to garden phlox in appearance and cultural requirements, but it is earlier flowering, has darker green leaves, conical flower heads and better mildew resistance. Plants are generally 2 to 3 feet tall. Spotted phlox is native to Iowa. It is most commonly seen along roadsides and prairie swales in the northeast part of that state, but it is grown throughout the Northeast as well. The species has mauve-pink flowers. Excellent cultivated varieties include ‘Alpha’ (rose-pink flowers with darker eyes), ‘Omega’ (white with pink eyes), ‘Miss Lingard’ (white), and ‘Rosalinde’ (purple-pink).

Dr. Leonard Perry of the University of Vermont has put together a great listing of numerous species of phlox including notes on mildew resistance, propagation, heights and flowering periods. You can see his listings online at www.pss.uvm.edu/pss123/perphlox.html and make sure you check out www.chicagobotanic.org/downloads/planteval_notes/no13_phlox.pdf. for one of the most comprehensive evaluations of phlox varieties.

Keep growing! Phlox are wonderful plants.

*Andrew Messinger has been a professional horticulturist for more than 30 years. He divides his time between homes and gardens in Southampton, Westchester and the Catskills. E-mail him at: Andrew@hamptongardener.com. The Hampton Gardener is a registered trademark.

Facebook Comments