The Homeowners Column

The Homeowners Column

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Garden Phlox: a perennial favorite

Photo of Sandra Mason

Sandra Mason
State Master Gardener Coordinator
slmason@illinois.edu

Garden phlox (Phlox paniculata) conjures up images of English country gardens and grandmas in house coats, but don't cast off these plants as old timers. Their fragrance and multitude of colors are a perfect fit for sunny modern gardens. With a hundred possible cultivars garden phlox includes all manner of colors in shades of pink, salmon, purple, lavender, scarlet, red and white. Some possess a contrasting colored center eye such as the popular 'Eva Cullum' with large clusters of pink flowers with dark red eyes and 'Bright Eyes' with pale pink flowers and crimson eyes. The flower panicles can reach a whopping 8 inches wide.

Most cultivars are 3-4 feet tall with a few such as 'Eva Cullum' and 'Red Riding Hood' at 2 feet. The taller ones may need staking or stiff companion plants such as lilies to keep them upright. A quick hair cut in early June will also keep them shorter to reduce the need for staking.

One problem with garden phlox is their susceptibility to the fungal disease powdery mildew. Generally plants don't die from the disease; however, leaves develop a powdery film then become unsightly brown corpses dangling on the stems. Sometimes I do a quick strip of the dead leaves with my hand. Their bare naked stems are on display, but they look tidier.

To reduce disease divide clumps in spring to keep 5 or 6 strong stems in each clump, try to provide good air circulation by not crowding plants and irrigate base of plants instead of leaves. When selecting garden phlox choose powdery mildew resistant cultivars such as 'Katherine' with her lavender flowers on 2-3 foot tall plants and the reliable white flowered 'David'.

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Several additional perennial species of phlox are available in various sizes from 6 inches to 3 feet tall and include late spring to summer flowering. All species are North American natives.

Short and sweet annual phlox (Phlox drummondii) is often seen in containers. I fall in love with these plants every spring; however, the honeymoon is quickly over due to their overall lack of vigor. Many of the newer cultivars of annual phlox are reported to be superior performers. Our Master Gardener Plant Trial Tattler Ann Tice reports in 2015 trials Proven Winners Phlox 'Intensia White Improved' was delightful in June and fabulous in July. She describes tons of fluffy white blooms. For your viewing pleasure it is planted in the flower bed west of the Idea Garden shed.

The ubiquitous flowers of moss phlox (Phlox subulata) are a signal of spring's arrival. The iridescent mats of pink, blue, purple, red or white flowers flash in gardens neighboring mailboxes, front doors and rock walls generally left lifeless most of the year. Full sun, well-drained soil and benign neglect suit the squatty moss phlox just fine.

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In May 2015 our native woodland phlox (Phlox divaricata) put on a fabulous forest show at Allerton Park in Monticello. The light to dark blue flowers decorated each nook and cranny of the forest floor. Their fresh sweet perfume chased out the dark, dank odor of winter. Its very usable height at just 12 inches tall and its shade loving ways translates into a plant deserving more use in gardens. Cultivars of woodland phlox include: the hearty blue/lilac flowers of 'Blue Dreams'; the well-named 'Clouds of Perfume'; and 'Fuller's White' with its monstrous mass of white flowers a more applicable name might be 'Snow Drift'.

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Wild sweet William (Phlox maculata) resembles garden phlox; however, wild sweet William flowers earlier in summer, has darker green leaves and flower heads are more conical. As with garden phlox removing old flowers encourages reblooming. 'Miss Lingard' is an excellent white-flowered cultivar with great powdery mildew resistance.

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July is a perfect time to flock to the Idea Garden on south Lincoln Avenue in Urbana to enjoy the fabulous phlox.

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