Sandra Mason: Fabulous Phlox

Sandra Mason: Fabulous Phlox

Garden phlox (Phlox paniculata) conjures up images of English country gardens and grandmas in housecoats, 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 100 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 to 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 like lilies to keep them upright. A quick haircut 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 five or six strong stems in each clump, try to provide good air circulation by not crowding plants and irrigate the base of plants instead of leaves. When selecting garden phlox, choose powdery mildew-resistant cultivars like Katherine with her lavender flowers on 2- to 3-foot-tall plants and the reliable, white-flowered David.

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 that 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.

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 translate 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.

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.

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

Sandra Mason is unit educator, horticulture and environment, for the University of Illinois Extension, Champaign, Ford, Iroquois and Vermilion counties. Contact her at 801 N. Country Fair Drive, C, call 217-333-7672, email or fax 217-333-7683.

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