Tall Garden Phlox
For years, I’ve loved Tall Garden Phlox (Phlox paniculata). Like other passionate gardeners, I love the tall, straight stems that add height and dignity to perennial borders. I love the fact that it blooms in mid-summer after many perennials have succumbed to summer heat. I love the way butterflies cluster around the big rounded flower heads, made up of dozens of small, perfect blooms that also attract hummingbirds. I love the variety of luscious colors, which breeders have expanded over the years from the whites and washed-out pinks of the natives to brilliant reds, deep purples, rich pinks, soft lavenders, and coral tones. I love the varieties that have a sweet aroma.
However, as much as I love this plant, I have hated the foliage, which generally becomes gray and shriveled with mildew. Breeders have worked diligently to improve the disease resistance of phlox, and over the years many varieties have been released that claimed “mildew tolerance.” I’ve generally been disappointed in their performance here in hot, sultry Indiana summers, despite spraying leaves with baking soda and leaving plenty of air space around them. Fungicide will generally control mildew, but I refuse to use such chemicals in my garden, and especially on plants that attract fragile butterflies. Fortunately, there are now varieties with much better resistance.
Phlox paniculata is native to the eastern regions of North America, where there are more than forty species. It was quickly taken by plant hunters to Europe, and by the late 17th century it had traveled from the gardens of the wealthy into the cherished plots of the cottagers. Growers began selecting for stronger colors and breeders began crosses to do the same. Along the way, flowers became bigger, or marked with centers that were paler or darker tones. Eventually, phlox with leaves variegated with gold became the rage. Unfortunately, as many other qualities were enhanced, the lovely fragrance of the native plant was lost.
As time passed, the wealthy turned from perennials to exotic annuals and tender plants that were planted out in massive areas, often forming fancy patterns. Estate gardeners all over Europe pulled out perennials in favor of these new exotics. Thankfully, cottage gardeners could not afford such a luxury so the wide selection of phlox varieties was saved. Soon, visionary gardeners such as Gertrude Jekyll and Margery Fish praised the merits of perennials and brought them back into favor.
Breeders went back to work and as flower heads became larger, some gardeners complained that the plant tended to fall over, especially after hard rains, requiring staking. Breeders responded by producing shorter plants, to the point that today there are many varieties that are only 15”. These are being touted for containers and for today’s smaller gardens.
Tall Garden Phlox prefers a sunny location, although some will tolerate light shade, and rich, well-drained soil. Eventually, the centers can become overcrowded and spindly, so the entire plant should be lifted every three to four years and only the outer robust clumps returned to the garden. Ideally, the phlox should be moved to avoid disease, but at least amend the soil with compost and fertilizer if returning clumps to the same location.
This plant generally blooms in July and August. However, by pinching a few stems when they are six to eight inches tall, and a few more when they are ten to twelve inches tall the display can be lengthened. When the plant has finished blooming, cutting it back may produce another display later in the fall where growing seasons are long. Pinching out spindly stems will send needed energy to the others, producing larger flowers on stronger stems. Any seedlings that appear should be removed, since they will not be true to the parent and generally revert back to their mildew-prone foliage and flowers with washed-out colors.
In the Victorian language of flowers, phlox symbolizes “sweet dreams” or “a proposal of love.”
Some of the varieties that are available for today’s garden are:
Alexandra 28”, rosy red with a small silvery center, patented
Aureole 20”, fuchsia pink petals are drop-resistant, patented
Baby Face 18”, clear pink with hot pink eye, mildew resistant
Becky Towe 20-30”, variegated gold & green foliage, rose with dark eye, patented
Blue Boy XXXXX lavender blue
Blue Paradise 24-36”, flowers open pale blue, darken to violet-blue, fragrant
Blushing Shortwood 24-30”, pink & white blooms
Bright Eyes 24”, showy salmon-pink with a red eye, fragrant, mildew resistant
Cosmopolitan 15” pink flowers with bright red eye, nearly mildew resistant, patented
Danielle 16”, pure white foliage
Deliliah 24”, deep red-purple bloom, excellent for mildew resistance
David 24-36”, pure white, highly mildew resistant, fragrant, patented
David’s Lavender 24-36”, jumbo 8” soft lavender-pink flowers, patented
DoDo Hanbury Forbes XXXX pink with red eye
Eva Cullum 24-48”, pink with a darker eye, mildew resistant
Flame series 15-18” comes in coral, pink, purple or violet, fragrant, patented
Franz Schubert 36”, lilac-blue with a “red” eye. Named by Alan Bloom
Grenadine Dream 20”, large clusters, non-fading red-purple flowers, strong stems,
Jade 20”, unusual white florets edged with lime green, drop resistant petals, patented
Jeff’s Blue 24”, late flowering, sweet fragrance, compact
Jeff’s Pink 24”, late flowering, sweet fragrance, compact
Junior Dance 18”, coral pink blooms, fragrant, patented
Junior Dream 18-22” pinkish purple flowers, fragrant, patented
Laura 24-48”, showy 6” lavender-purple with white centers, fragrant, mildew resistant
Little Boy 15”, lilac blue, white eye, nearly mildew resistant
Minnie Pearl 15-20”, pure white, compact, early blooms, disease resistant, patented
Mystic Green 22”, light green florets, compact, mid-season bloomer
Nadia 28”, purple stems & new foliage is purple then green, pink flowers with dark eye,
Nicky 44”, deep purple, the darkest of all, sweetly fragrant, good mildew resistance
Norah Leigh 28”, green & white variegated foliage, lavender-pink bloom
Orange Perfection 30-36”, coral-toned, fragrant, drought tolerant.
Peacock Cherry Red 18-24” soft red, disease resistant
Peacock Purple Bicolor 18-24” Lavender with white star center
Peacock White 18-24”, pure white, compact
Peppermint Twist 16”, pink & white
Picasso 20”, pink and white streaked flowers, compact, good in containers
Pink Flame 18”, pink
Pink Lady 20-24”, non-fading rich pink, compact
Pixie Miracle Grace 15-20”, lavender-purple with white eye, fragrant, patented
Pixie Twinkle 15-20”, baby pink with dark pink eye, fragrant, patented
Prime Minister XXXX soft pink with dark pink eye
Purple Flame 12-18”, purple
Red Riding Hood 18”, one of the early short ones, bright red flowers
Shockwave 12-18”, variegated yellow & green foliage, lavender blooms with white star
Sport of David’s Lavender. Patented.
Starfire 30”, brightest red, bronze-toned foliage, long-blooming
Stars & Stripes 22”, light pink flowers, hot red star, slightly fragrant, mildew tolerant
Tiara 22”, double white blooms, fragrant, patented
Valentina 32”, soft rose with darker eye, robust, patented
Watermelon Punch 15”, very compact, salmon-pink with white eye, patented
White Flame 16”, striking white with a red eye
Younique White 16”, very compact, pure white, patented