'Blue Boy' Phlox
"And quick leaves cast a shimmer of green
Against our whited walls,
And in the phlox, the dutious bees
Are paying duty calls."
-Christopher Morley
(1890-1957)
(1890-1957)
Variously called Garden Phlox, Summer Phlox, Tall Phlox, Perennial Phlox, Summer Phlox, Autumn Phlox, Panicled Phlox, or Sweet William, P. paniculata is the showiest of the genus, with many cultivars in sundry colors. 'Blue Boy' is purple-blue or lavender with pale (to nearly white) center.
'Blue Boy' grows in our neighbor Sue's front yard in great numbers, as she has been dividing clumps for years. We could get a start of it from her during the next division, but since they're growing right on the other side of the fence from us, we get plenty of enjoyment seeing hers. These attract butterflies & are spectacular for bouquets.
The one-inch flowers occur in clusters five or six inches big, & each clump can produce a great many flowers in July & August, with a lesser rebloom possible with deadheading. They have a mild pleasant scent that can sour a bit when the flowers are fading. In fullest bloom they stand a good four feet tall, & clumps easily spread to over a foot width but should be divided by the time they reach a two-foot width.
Garden Phloxes were developed from the wildflower native to much of the eastern half of the United States. It was very soon the object of interest in Colonial America as a garden ornamental.
These perennials like rich moist well-draining soil, but an old clump can be surprisingly drought tolerant & still perform well. It always does best in full sun, but if it finds itself in partial shade it will still flower fairly nicely.
Among the varieties most resistent to mildew are 'Blue Boy' & the white 'David.' In a good location they should not be bothered by powdery mildew at all, but in a spot with poor air circulation or overcrowding or in a region with persisting high humidity, or if grown in company with other plants equally susceptible to mildew (such as beebalms), powdery mildew can become a burdon.
A spraying every few weeks of dilute milk (one part skim milk to five parts water) will keep powdery mildew at bay much better than does sulpher or commercial fungicides. But afflicted clumps should probably be moved to an airier location, & foliage clipped entirely to the ground to start over. Mildewed foliage should be burnt or bagged to discard, not composted, as the spoors can survive compost heat.
Phloxes sometimes self-seed but don't grow true to the parent & are most often of inferior color. But they are super easy to propogate from cuttings of softwood stems, shoots taken with a bit of root, or leaf nodes taken spring or summer, & even more easily cultivated by dividing the roots in late autumn or early spring. The root so easily regenerates that if you dig up a clump, divide it, & move the phlox elsewhere, it'll almost certainly reappear in the old location too.