PHLOX

Photo: Plant-growing.com

PHLOX

Caution! Flammable!

By Panayoti Kelaidis

Garden phlox come in three general categories: tall ones that bloom in late summer, little groundcovers sold everywhere that bloom in April, and the fantastic phlox that you cannot purchase anywhere, but which we ought to be growing.

Why flammable? Because the word Phlox comes from the Ancient Greek word φλόξ  which translates as flame—most appropriate for the occasional nearly scarlet cultivars of both creeping and tall phlox, though some of the other colors are also blazingly bright.  A happy planting of phlox can certainly warm the heart of any proud gardener, if not necessarily setting it on literal fire.

First the tall phlox.  I first came to know these in the garden of close family friends who came from Spain. They loved phlox so much that’s pretty much all they grew in their back yard—I’ll never forget walking out into that garden as a small child and seeing the masses of lavender-pink phlox (the older cultivars are often a shade of pink best described as “aniline”—harkening to faded Victorian girls’ dresses, or perhaps 1950’s plastic kitchenware, or the movie “Barbie”.) The smell was overpowering, especially at dusk. In retrospect, I populate this garden with sphinx moths—they had to have been there!  The flowers age a sort of gray-bluish shade (alas). I still grow some of these old cultivars—probably straight forms of Phlox paniculata from the wild—first because they’re very tough and second because I’m a sentimental fool.  The smell of summer phlox is transcendent— like innocence or purity should smell. Only really really strong.

Phlox paniculata Photo: Panayoti Kelaidis

Hybridizers have produced no end of cultivars in every shade of pink, purple, near blue, and darned near scarlet. There are dwarfish forms just a few feet tall and some will tower to five feet on rich soil that’s moist.  You see them in nurseries and garden centers all the time. I rarely see them in gardens. I especially recommend Phlox ‘David’, a tall white phlox that blooms for several weeks and has a lot of stamina.

Phlox 'David' Photo: Panayoti Kelaidis

I doubt if there’s a single garden center (except perhaps in Hawaii or the southernmost states) which doesn’t sell pink, lavender blue and white creeping phlox in April and May. These are enormous sellers for garden centers and I have seen them extremely effectively utilized in home gardens, especially on slopes, or among rocks in rock gardens. They only bloom a few weeks, but the rest of their year their soft mats of slightly prickly leaves make a pleasing groundcover. If you can look past the common three cultivars usually sold as the “Emerald” series, you can find a surprising range of cultivars of Phlox subulata and its close allies. These are well worth seeking out since they often have much brighter flowers (‘Crackerjack’) or unusual forms (‘Little Trumpets’) and some are more compact or otherwise unique. I find they do like slopes and something richer than typical rock garden or xeriscape conditions in Colorado. They are not xeric, needing occasional drinks especially in the hot summer months. Nevertheless, even the notorious snob, Reginald Farrer declared that the day creeping phloxes were introduced to cultivation should be declared a holiday. One that far too few gardens celebrate.

Phlox sublata Photo: Panayoti Kelaidis

The two primary categories of garden phloxes derive from only a handful of species—a fraction of the OTHER phloxes. Only the dreamy Phlox divaricata from the Eastern woods approaches true blue. A slowly spreading perennial for part shade and moist, rich soil, it is found regularly in nurseries.  Phlox drummondii is one of the few annuals in the genus; the typical wild form blooms for only a few weeks in spring and dies. But some hybridizing magicians have begun to select heat tolerant forms that can bloom for a long time—even months. I have planted these in containers where they make a good show most of the growing season, but then they do eventually die.

Phlox divaricata Photo: Panayoti Kelaidis

Phlox 'Crackerjack' Photo: Panayoti Kelaidis

The rest, including spectacular Mexican phloxes with scarlet or yellow flowers, the dozens of mat phlox of dry steppe in the West, and a bevy of unusual compact or willowy meadow forms are all  occasionally sold by specialist nurseries. Members of specialist plant groups like the North American Rock Garden Society occasionally propagate and offer these and other gems at their sales, which is one of the best reasons to join them.

Phlox condensata  Photo: Panayoti Kelaidis

Phlox sublata 'Scarlet Flame'  Photo: Panayoti Kelaidis

Phlox nana in Pat & Joel Hayward's garden Photo: Panayoti Kelaidis

One phlox in particular, Phlox nana, was offered for years by High Country Gardens and perhaps will again in the future. This compact, slowly spreading perennial thrives in xeriscapes, making slowly ramifying mounds to four or five inches and blooming pretty regularly from May to autumn Frost. Yes, Virginia, its flower color is an aniline pink. But I guarantee that should you find and grow this plant your pride will certainly be inflamed.

Panayoti Kelaidis is Senior Curator and Director of Outreach at Denver Botanic Gardens