(6/2) Who know there were so many plants called PHLOX? Some are spring, some are summer, some are shade and some are sun. Let’s define the differences of this plant genus.
The spring blooming phlox include P. stonoifera, P. pilosa, P. subulata, and P. divaricata. Phlox paniculata is the summer bloomer. All five of these species are native to Pennsylvania and Maryland. Also, phlox are bee and butterfly attractants. From early spring through summer there could be some phlox species blooming which provides a nectar
source for the early buzzers, as well as the hot weather flyers.
The two most common phlox species are subulata and paniculata. Phlox subulata is commonly called creeping phlox or moss phlox. This plant is a low ground cover type plant, stretching only to 12" tall. As with all phlox, it attracts butterflies. Blooming in May, colors of pink, purple and white cover the ground to welcome the month in full sun. It
is a great choice for a rock garden, to drape over a wall, or to use on a slope. When it’s not blooming, it has nice green foliage. Although it could be considered a ground cover, it doesn’t have stolens nor is it likely to spread beyond the breadth of the plant. They will reach 3 feet in width.
Phlox paniculata, the "other" common phlox, is very different than the creeping phlox. This is a summer bloomer, and depending on the cultivar, can be as tall as 18" up to 5’. This beautiful perennial requires full sun and good air circulation. It will bloom in June through July, and depending on the variety, can be blooming through till September.
This plant can be found in just about any shade of pink and purple as well as white. It requires well drained soils but does not tolerate dry conditions. A deep, rich soil is best.
The biggest problem with this species is powdery mildew. This is a disease that will cover the leaves with a white film. A very common problem for garden phlox, when the plant does not get enough sun or good air circulation, the disease will begin to spread. On the upside, this mildew does not kill the plant, and with the right garden design, the
foliage of the infected phlox can be hidden with plants in front of them.
A gardener has a few choices to control this disease. First, they can spray a fungicide listed for powdery mildew on phlox as soon as they see it. Follow the label instructions on the fungicide bottle to be sure it is mixed and applied properly and at the right time, at the right temperature. There are both organic choices as well as chemical
choices. The key is to read the label to be sure the product is listed for the problem and plant that is being controlled, in this case, mildew on phlox. Another easy thing to do is just cut the plants back and chances are the new foliage will be mildew free. Siting this plant becomes critical if trying to avoid mildew. Good air circulation is key. Be sure not to crowd
the phlox with lots of other plants around it, although planting some things in the foreground to hide potential mildew issues is a good idea. Mildew of phlox is different than mildews of other plants, so no need to worry about this mildew spreading to other types of plants.
P. paniculata has many, many cultivars. Some of my favorites are ‘Robert Poore’, ‘Jeana’, ‘David’, and ‘David’s Lavender’. All four of these varieties have been proven to be resistant to powdery mildew, a real plus. In my garden, I have found that to be true. ‘Robert Poore’ is 3’-4’ tall and has a red-purple flower. ‘Jeana’ is a pink flower, and
will get close to 5’ tall, great for a back of the border plant. When it’s in full bloom it is spectacular.
‘David’ is a white, fragrant flower, reaching about 4’ tall. Great planted close to a sitting area or entrance so the fragrance can be enjoyed. ‘David’s Lavender’ is, well, lavender. It also gets about 4’ tall, but not a fragrant. Both are mildew resistant. Both ‘David’ and ‘David’s Lavender’ have very large flowers on top of tall stems. Very
striking in any garden. ‘David’ has been my long season bloomer. I have seen him bloom well past August and into September.
Although ‘David’ is spectacular, ‘Jeana’ has become my favorite garden phlox. She is a tall one, about 5 feet. She has pink flowers and very abundant. Although the flowers are not nearly as big as’ David’ or ‘David’s Lavender’, ‘Jeana’ has lots and lots of flowers giving a huge display of color. Mildew resistant for sure, she looks great in the
rear of any border, creating a backdrop acquired by few. ‘Robert Poore’ is very nice red/purple flowers. Although my experience is that it is harder to find in nurseries, it’s well worth the search for its mildew resistance. Of all the phlox that I’ve grown,’ Robert Poore’ has been the best at mildew resistance, which puts it on the top of my list of varieties.
Garden phlox mix well with other summer plants like rudbeckia and coneflowers. Add some Sedum ‘Matrona’ to the mix and you have a beautiful summer garden. Of all the phlox, the paniculatas are my favorite because of the colorful display.
Phlox divaricata is a spring bloomer that prefers dappled shade. It likes deep, well drained soils. Often called creeping phlox (yes, the same common name as Phlox subulata – a good reason to use botanical names) this sweet plant blooms in the spring. The flowers rise about 12" above the low growing foliage in April. Typically you will find
varieties with pink and lavender flowers. It works great for a shady wall, or ground cover, however, it’s not a rapid spreader. It will reseed, although not incredibly quickly. This is a nice woodland plant for spring color.
In addition to Phlox divaricata, Phlox stolonifera is also a spring bloomer. This very shallow rooted plant is also a ground cover that spreads more rapidly than divaricate when it’s happy. This one likes full shade so does great in a woodland garden. As the name indicates, it will spread by stolens. Shades of purple and lavender will cover this
plant in April. Unlike P. divaricata, P. stolonifera’s flowers stay close to the foliage, where P. divaricata’s flowers hover above the foliage.
Phlox pilosa is another spring bloomer but unlike the last two mentioned, this one likes part sun to full sun and drier soils. Its common name is prairie phlox, indicating that it grows well in a sunnier location. Again the flower color is in the purple/lavender family.
A great plant Genus, there is a phlox for every occasion. Sun, shade, spring, summer…a phlox just may fit the bill.
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