Tall Garden Phlox – Image Courtesy Walter’s Gardens

Tall Garden Phlox – From “magenta obscurity” to the most prominent place in the floral world

Many gardeners see the gorgeous Tall Garden Phlox advertised in books or magazines and immediately draw the wrong conclusion that it is much too beautiful and finicky to grow in the western Mountains. Not true! Not only is it cold-hardy, but this breathtaking perennial is also deer-resistant.

The slight alkaline pH of the Rocky Mountains is chock-full of minerals and is only one reason Phlox grows so well. The rigid stems of Phlox stay shorter and stockier and Phlox blooms longer in the cooler temperatures of higher elevations. The Western Mountains are often referred to as a cool, arid desert climate which discourages mildew, a disease that attacks Phlox in areas of constant humidity, so this is another reason they perform so well.

Phlox originated as a wildflower in the mountains and still grows there. The pale lavender wild florets of Phlox on the canyon floors are about seven-inches tall with slender stems and trumpets but any Phlox that germinates in rocky openings grows as a tiny, four-inch cluster and their colors are muted and mainly white. Phlox is no longer a simple wildflower but has been cultivated to bloom with lovely rounded flowers in delectable shades of pinks, magentas, reds, orchids, lavenders and white. In the hybridizer’s zeal for bigger blooms and more colors, many Phlox have lost their enchanting fragrance. It’s interesting that the most fragrant Phlox are the ones bred from the old fashioned, untouched healthy stock. If a Phlox is not described as mildew-resistant and fragrant, do not waste time adding it to your garden for it will be disappointing. Hybrid Phlox that re-seeds reverts back to the washed-out wildflower colors and develops into a hard-to-eliminate weedy plant.

Phlox breaks spring dormancy late, which protects it from getting damaged by the West’s freeze/thaw cycles that ruin so many other perennials.. The hardiest, most robust of the Phlox cultivars is the white, Phlox ‘David’ which won the prestigious Perennial Plant of the Year Award. Another splendid Phlox is the old fashioned ‘Bright Eyes’ with huge pink florets with scarlet centers. Both of these Phlox are highly fragrant, mildew resistant, totally dependable, and stunning in the garden.

Here, “Midwest Gardener,” Jim shows how to deadhead phlox to encourage longer blooming into late summer.