Phlox paniculata
Tall Garden Phlox
“This plant is a native, and with true American perspicacity and enterprise has forged his way from magenta obscurity to the most prominent place in the floral world.”
from ‘My Garden’ by Louise Beebe Wilder, 1916
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Phlox Culture and Propagation | Phlox Powdery Mildew Problems | Phlox Lists
Reasons why we love Phlox!
Phlox are not only among Rachel’s favorite perennials; they have been favorites in American gardens for well over 100 years. It’s not hard to see why. They are long blooming, hardy and long-lived, easy of culture, often fragrant and never need staking. They come in a range of heights from two to five feet, and produce huge billows of bloom in mid-late summer, in a range of colors from pure white to red, with nearly every shade of pink, lavender, salmon and purple in between. They grow happily in most parts of the country and, properly planted and sited, they are largely pest and disease free, and provide decades of effortless bloom.
167 Cultivars and Climbing!
Since starting the nursery in 1980 we have been collecting Phlox paniculata cultivars, focusing on the heirloom types, and currently there are some 167 varieties growing here in the gardens. We have gathered them from local nurseries, New England gardens, mail-order sources, and even gone to Europe to acquire some of the more elusive heirlooms. Many new cultivars have been released in recent years, as the genus regains its popularity, and we are trying these ones out too. Some of our most popular phlox have been discovered in local country gardens, the plants having been kept going for decades by dedicated gardeners. We continue to actively search out the old varieties, and would be delighted to receive any leads from our readers.
Not all of the phlox cultivars are always available for purchase, while we assess and propagate them, and some of them just live here as a sort of horticultural library, but the mail-order list offers around 60 cultivars, and over 70 are typically available potted on-site. In 2024 we are doing less plant shipping than previously, and there are about 25 listed on the order site now, while at the nursery there are typically 60 or more cultivars potted up for sale.
Call ahead! If you are coming from a distance to purchase plants, I strongly encourage you to send us your wishlist, and we will set plants aside for you, and can even dig some of the obscure cultivars up to order. With this many plants, we never have all of them potted up at the same time. Special orders for rare phlox from the list – please contact us, and we can propagate some. The lead time could be three months or more, depending on the time of year.
A Brief History of Phlox
Historically, Phlox paniculata was perhaps the most prominent plant in perennial gardens from the turn of the century through the 1940s. As some have put it, “Phlox Ruled”! Although native to North America, it was the Europeans who first recognized the potential in our simple magenta or white wild phloxes, and who experimented with selecting and breeding, then re-importing the improved types back to the U.S. Two very notable names associated with the development of phlox are Karl Foerster and B.H.B. Symons-Jeune. The American breeders made serious contributions as well, and references have been found for over 800 named varieties! That may sound like a lot, but there are now over 4,000 named varieties of Hosta, and an astounding 68,000 Daylilies out there. (Speaking of those 800 phlox – it’s unbelievable that they were all unique. Like those thousands of daylilies, there are only so many distinctive combinations possible, and many unremarkable or duplicate varieties were probably hustled into the market. Just like nowadays, people lose plant tags and wind up re-naming plants. It remains a problem.) The apogee of phlox planting came in the early 20th century, but in the 1940s there were still over 220 named varieties available in New England nurseries. Most of these have sadly gone missing. Phlox suffered a downturn in popularity from the 1940s to the 1980s, when perennial gardening in general came to be regarded as old-fashioned and rather quaint, and this is when so many old cultivars were lost. In recent years, however, there has been growing interest, and many new cultivars are being developed, with recent focus on producing dwarf plants, and increasing mildew resistance. There is great interest in Phlox in Europe, and one Lithuanian nursery boasts an astounding 1800 cultivars!
White-lined Sphinx Moth, also known as Hummingbird Moth, is a Phlox pollinator.
Phlox Culture and Propagation
Phlox prosper in a cool sunny climate, well-watered, in rich sweet soil. In much of the country, they will thrive in full sun, although partial shade is fine, as long as the plants receive at least 4 hours of direct sun. In the southern or hot climes, partial shade is recommended. The soil should be rich and slightly sweet (alkaline), so if your soil tends towards the acidic side, a regular application of lime is recommended, say every two or three years. The plants should be set in quite rich soil, enriched with compost or aged manure. This type of soil will also hold water well, an important feature, for phlox do not do well in hot dry soils. Mulching will assist in water conservation and in keeping the soil cool. Because they are heavy feeders, even beautifully prepared soil will decline after four or five years, and it is best to plan on resetting your plants on a regular basis, every four or five years. The plants should be lifted out (in fall or early spring), divided into several chunks, replanting only one of those chunks in the old spot. What to do with the remainder? Either expand the phlox border, or give them to a neighbor.
Phlox are very easy to increase by simple division, in late summer or early spring. Commercial growers tend to propagate them using root cuttings taken in late summer. Stem cuttings can be taken in early midsummer, if you have a good clean setup in a propagation dome or greenhouse.
While phlox start easily from seed, and often self-sow into the garden, it is rare for the seedlings to have the same coloring and habit as their parent. In fact it is good policy to deadhead your phlox before they go to seed, as those little self-sown seedlings tend to grow up into vigorous plants of a decided magenta hue and can, in a few years, crowd out the mother plant. In our fields we will go through every year looking to uproot these rogues, and we find new ones every year. (Of course once in a while these seedlings create exciting new plants, so we like to pay attention before we pull, and so should you!)
Phlox Problems
Powdery Mildew – The number one complaint, and what you can do about it.
Control Powdery Mildew with Proper Culture
Many people find their phlox plants are troubled with powdery mildew, a white fungus that bespeckles or coats the leaves, typically in high summer. Although it is never fatal, it can be unsightly, and may lessen flowering and lead to leaf drop. I first want to remind us how lucky we are that this is the biggest problem with phlox, compared to so many serious problems other plant may have, all those beetles, thrips, soots, aphids, weevils and so forth. Mildew tends to be a greater problem in regions with high humidity, but will also affect phlox that are planted in dry soils. I consider that it is pretty much endemic, and if your phlox are prone to it, it will turn up in every garden sooner or later. What can you do?
Hide it!
Well, to take a passive approach, it is perfectly acceptable to grow other plants in front to hide the unsightly foliage. The mildew that affects phlox is specific to phlox, and will not spread to other species, although if the environmental conditions are favoring phlox mildew, you could well see related different mildews turning up on other plants.
Plant Resistant Cultivars!
Now, some phlox cultivars are nearly impervious, even in rotten conditions, and others get it at the drop of a spore, even in excellent conditions. Most of the heirloom varieties have proved extremely resistant, having shown their value to generations of gardeners. Choose varieties that have good mildew resistance, of which there are quite a few available (see list below). Be somewhat cautious in accepting the claims about brand-new cultivars – a skeptical eye has its place, as I’ve learned over the years. I try to grow a new cultivar a couple of years before pronouncing judgment.
Above All, Keep your Phlox Happy, in Cool and Well-watered Soils
Growing phlox in a suitable environment appears to be the most important thing in preventing mildew. I have been observing phlox for 36 years now, and have developed some opinions that are contrary to the standard gardening advice. I don’t thin the stalks or bother to avoid nighttime watering – after all, nature ‘waters’ the plants every night with dew. I have found that, for the most part, happy plants simply resist mildew. Stressed plants will usually develop some degree of mildew. What are the proper conditions that make them happy, healthy and mildew-free?
What makes them happy is to be in cool location, preferably with a little partial shade from the hot afternoon sun, and in a humus-rich soil. Did you know that their native situation is woodland, not out on the dry open prairie? Partially shaded locations are fine, and indeed recommended in climates hotter than Vermont (which is nearly everywhere). When planted in full sun, have other plants grow about the bases, to keep the soils shaded. By all means water them when the weather is dry. The plants should be lifted out every five years or so, and reset in newly and heavily enriched soil (compost or aged manure). Phlox detest hot and dry soils. Keeping a phlox in an exposed hot dry soil, with no surrounding vegetation or mulch, virtually guarantees mildew (and spider mites too), but if you move a plant from hateful to lovable conditions, it should bounce back beautifully the next year, and show little or no spots at all.
Spray Treatment for Powdery Mildew
There may be times or locations where you need, or want, to do more. If you decide to treat the mildew, try the following:
- Horticultural Oil – We have found that horticultural oil works very well as a preventative, and to contain the spread of the fungus, simply by smothering it. This is what we use on our potted phlox, which suffer unavoidably from dry and hot conditions in their black plastic pots. We spray every two weeks with a light summer oil, which protects the leaves, and doesn’t wash off easily in the rain. Plus, it makes the leaves nice and shiny. Both petroleum-based and organic oils, such as those made of canola and soybean work well. (Pharm Solutions is one source for these organic oils.)
- A 10% milk solution in water (use low or no-fat milk, fresh or dried. Mix 10 parts water to one part milk). Should be sprayed weekly.
- Baking soda solution (mix 1 Tbsp plus ½ tsp of liquid soap in 1 gallon of water). Apply weekly.
- Commonly available fungicides such as Serenade will do the trick too – ask at any garden center.
- As a rule, these treatments should be used as preventatives, or at the first sign of spotting. One should also remove and trash mildewed leaves from the garden periodically and at year’s end, as it doesn’t hurt to reduce the quantity of innoculum in the garden. I would be grateful to hear from fellow gardeners of other successful treatments.
Other pests – Spider Mites and 4-legged Nibblers
Phlox have very few insect pests. The only pest that is commonly seen is spider mite, which congregates on the underside of leaves, causing leaves to curl, dry up and fall off. You can detect this in the early stages, by observing a slight dusty sootiness on the undersides. They appear to be a problem only when the situation is too hot and dry, and so again it is remedied by improving the soil and increasing the watering. For an immediate response, a good blast of water on the leaves is helpful.
Herbivores love Phlox too!
Many animals, especially deer, consider Phlox a treat to eat, and this can be a real problem, but much depends on your location. Deer are the bigger culprits, as they can be found in both rural as well as suburban areas. There are many sprays available to buy, and I suggest you ask your neighbors, or garden club, to glean info about which sprays actually work in your area. A resident dog helps hugely against every forager, but with heavy deer pressure, many people are driven to fence. Rather than building an 8 ft permanent fence, at serious expense, have a look at the cheap and easy method of using fishing line, which works by spooking the deer (a good online video explanation can be found by searching MI Gardener Deer Proof Garden Fencing).
Interestingly, here at the nursery we do not have a deer problem. We are at the village’s edge, and separated from the woods by a broad hay field – evidently the deer don’t think it worth the risk, as they have ample foraging in our rural area.
PHLOX LISTS (by color, fragrance, height, and mildew resistance, plus a list of our heirloom phlox)
Friends, I do my best to accurately compile these lists, and usually conscript a friend or two to opine, but still find myself shifting plants from one category to another, according to succeeding observations. In particular the color of a phlox can shift substantially according to the light conditions, and the age of the floret. I try then to just give the overall impression of the color. The fragrance of phlox seems to be most pronounced in mature flowers, not newly opened florets.
RACHEL’S TOP TWENTY PHLOX:
This is not an easy list to create! These are my current favorite cultivars, for reasons of vigor, mildew resistance or just plain gorgeous color that I wouldn’t want to be without.
Bright Eyes, Cabot Pink, Caspian, David, Dorffreude, Glamour Girl, Hot September Pink, Jeana, Lizzy, Midsummer White, Minnie Pearl, Miss Mary, Monica Lynden-Bell, Old Cellarhole, Popeye, Prime Minister, Robert Poore, Salmon Beauty, Sarah Cummings, Widar
PHLOX BY COLOR
Check out our Phlox Group Portraits page, where you can see many of the blossoms side by side!
Soft Pinks: Balmoral, Bright Eyes, Blushing Bride, Cinderella, D.H.Forbes, Europa, Eva Cullum, Eva Foerster, Fairest One, Fairy’s Petticoat, Fashionably Early Princess, Flame Light Pink, Flamingo, Hercules, Lady Clare, Little Princess, Mile High Pink, Miss Ellie, Miss Holland, Miss Pepper, Monica Lynden-Bell , Prime Minister, Old Cellarhole, Opalescence, Rosalinde, Salmon Beauty, Speed Limit 45, Thai Pink Jade, Uptown Girl, Zurstock Rose.
Strong Pinks: Alexandra, Cabot Pink, Candy Floss, Cleopatra, Coral Queen, Cover Girl, Dorffreude, Fashionably Early Flamingo, Glamour Girl, Hesperis, Hot September Pink, Jeana, Jules Sandeau, Lizzy, Mrs. A.E.Jeans, Natascha, Newbird, Rijnstroom, Robert Poore, Rosalinde, Rosy Veil, Shortwood, Sir John Falstaff, Ultraviolet.
Lavender/Blue Shades: Amethyst Pearl, Blue Boy, Blue Lagoon, Blue Spot, Blushing Shortwood, Cool of the Evening, David’s Lavender, Eventide, Fashionably Early Lavender Ice, Flame Blue, Franz Schubert, Hesperis, John Fanick, Katherine, Lilac Glory, Opening Act, Progress, Starry Skies, Wilhelm Kesselring.
Purple/Blue Shades: Amethyst, Autumn Joy, Blue Paradise, Cover Girl, Delilah, Early Purple, Ending Blue, Flame Purple, Hesperis, Jr. Dream, Laura, Little Boy, Miss Kelly, Nicky, Pixie Miracle Grace, Russian Violet, Sarah Cummings, Wendy House, Widar.
Whites (or Largely So): Anne, Backlight, Blushing Bride, David, Delta Snow, Fashionably Early Crystal, Flame White, Flame White Eye, Flower Power, Jr. Surprise, Kirmeslandler, Midsummer White, Minnie Pearl, Miss Jill, Miss Lingard, Miss Universe, Mother of Pearl, Mt. Fujiyama, Omega, Pink Bud, Popeye, Shorty White, White Admiral.
Salmon/Orange Shades: Brigadier, Caspian, Jr. Dance, Mary Fox, Orange Perfection, Prince of Orange, Salmon Beauty, Sandra, Windsor.
Reds: Charles Curtis, Flame Coral, Grenadine Dream, Lord Clayton, Miss Mary, Red Magic, Red Riding Hood, Red Super, Spitfire, Starfire.
Bicolors: Aureole, Natascha, Mystique Green, Natural Feelings, Peppermint Twist, Picasso, Sherbet Cocktail, Twister.
Variegated Foliage: Crème de Menthe, Darwin’s Choice, Norah Leigh, Shockwave.
ESPECIALLY FRAGRANT PHLOX:
Cinderella, David, Ending Blue, Fairy’s Petticoat, Franz Schubert, Katherine, Midsummer White, Mile High Pink, Miss Pepper, Miss Universe, Old Cellarhole, Russian Violet, Starfire, Thai Pink Jade, Widar.
BEST MILDEW RESISTANCE:
Amethyst Pearl, Blue Lagoon, Blushing Shortwood, Bright Eyes, Caspian, Cinderella, David, David’s Lavendar, Delta Snow (the very best), the Fashionably Early series, Glamour Girl, Hot September Pink, Jeana (also the very best), John Fanick, Midsummer White, Minnie Pearl, Miss Lingard, Miss Universe, Natascha, Old Cellarhole, Omega, Robert Poore, Rosalinde, Russian Violet, Shortwood, Speed Limit 45, White Admiral, Widar.
HEIRLOOM PHLOX CULTIVARS – all dating from 1950 or earlier:
Amethyst (by 1949), Blue Boy (by 1945), Brigadier (1940s), Caroline van den Berg (by 1945), Charles Curtis (c. 1945), Cinderella (by 1949), Dorffreude (1939), Europa (1910), Eventide (by 1942), Jules Sandeau (by 1934), Miss Lingard (by 1889), Newbird (by 1931), Prime Minister (1912), Prince of Orange (1950), Progress (by 1944), Rijnstroom (1910), Rosalinde (1920s), Salmon Beauty (by 1945), Spitfire (by 1940), Widar (by 1931), Wilhelm Kesselring (by 1931).
BY HEIGHT, THE SHORTEST AND TALLEST PHLOX
Short Phlox, 3 ft or under: Amethyst Pearl, Anne, Aureole, Blushing Shortwood, Delilah, Fairest One, the Fashionably Early series, the Flame Series, Jr. Dance, Jr. Dream, Jr. Surprise, Little Boy, Little Princess, Miss Lingard, Miss Mary, Natascha, Omega, Red Riding Hood, Shorty White.
Tall Phlox, 4-5 ft: Bright Eyes, Cabot Pink, David, David’s Lavender, Delta Snow, D.H.Forbes, Fairy’s Petticoat, Hot September Pink, Midsummer White, Miss Holland, Miss Universe, Mt. Fujiyama, Pink Bud, Salmon Beauty, Sherbert Cocktail, Sir John Falstaff, Spitfire, White Admiral, Widar.
Very Tall Phlox, to 5 ft or more: Caspian, Hesperis, Kirmeslandler, Mile High Pink, Old Cellarhole, Robert Poore, Russian Violet
